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Modelling residential electricity demand in the GCC countries Tarek N. Atalla a, , Lester C. Hunt a,b a King Abdullah Petroleum Studies and Research Center (KAPSARC), Riyadh, Saudi Arabia b Surrey Energy Economics Centre (SEEC), University of Surrey, UK abstract article info Article history: Received 22 December 2015 Received in revised form 19 July 2016 Accepted 26 July 2016 Available online 3 August 2016 JEL classication: C22 Q41 Q43 This paper aims at understanding the drivers of residential electricity demand in the Gulf Cooperation Council countries by applying the structural time series model. In addition to the economic variables of GDP and real elec- tricity prices, the model accounts for population, weather, and a stochastic underlying energy demand trend as a proxy for efciency and human behaviour. The resulting income and price elasticities are informative for policy makers given the paucity of previous estimates for a region with particular political structures and economies subject to large shocks. In particular, the estimates allow for a sound assessment of the impact of energy- related policies suggesting that if policy makers in the region wish to curtail future residential electricity con- sumption they would need to improve the efciency of appliances and increase energy using awareness of con- sumers, possibly by education and marketing campaigns. Moreover, even if prices were raised the impact on curbing residential electricity growth in the region is likely to be very small given the low estimated price elasticitiesunless, that is, prices were raised so high that expenditure on electricity becomes such a large pro- portion of income that the price elasticities increase (in absolute terms). © 2016 King Abdullah Petroleum Studies and Research Center (KAPSARC). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Keywords: GCC residential electricity demand Structural time series model Impact of weather and exogenous underlying energy demand trend (UEDT) 1. Introduction In a world with increased international focus on energy use, compar- ing energy demand behaviour across countries can inform decision makers about their country's relative performance and opportunities for future improvement. In particular, understanding the drivers of residential electricity demandand by association the intensity and productivity of residential electricity usehas become increasingly im- portant for policy-related international cross-country comparisons. However, the contrasts are arguably more meaningful when compari- sons are normalized for uncontrollable exogenous factors, weather being a prime example. Given the rapid development of electricity using appliances (such as air conditioners), the interdependency between climate variation and residential electricity consumption has, in all probability, increasedwith space heating and cooling representing the largest share of building energy consumption in many countries (Pérez-Lombard et al., 2008). Moreover, analysing the effect of weather on residential electricity demand is of special relevance to the Gulf Cooperation Council (GCC) countriesBahrain, Kuwait, Oman, Qatar, Saudi Arabia, and the United Arab Emirates (UEA)which, by virtue of being located near the tropics, are characterized by one of the hottest and most arid climates in the world. Furthermore, residential electricity consumption in the GCC coun- tries has increased rapidly over recent decades amid a steep increase in population and relatively fast economic growth (Squalli, 2007; Reiche, 2010). This was at a time when residential electricity prices in the GCC were administered by member countries and, as such, xed in nominal terms for a number of years between adjustments. Within this context, this paper attempts to model residential electricity demand for the six GCC countries in order to estimate the income, price, and population elasticities as well as controlling for the effect of climate conditions. The model utilized recognizes that electricity is a derived demand based on the demand for energy services such as heating, cooling, and cooking (Hunt and Ryan, 2015). Hence, in addition to the key drivers of income, prices, population, and weather, an explicit allowance is made for energy efciency and other exogenous effects by estimating a stochastic underlying energy demand trend, as suggested by Hunt et al. (2003a, 2003b). This paper is divided into ve sections as follows: after the Introduction, Section 2 discusses the background to the work and relevant previous literature, Section 3 details the methodology adopted, Section 4 discusses the data and estimation results, and Section 5 closes with a summary and conclusion. 2. Background 2.1. Residential electricity in the GCC countries Despite sharing many common traits, the GCC economies are not as macro-economically unied as might be assumed. Saudi Arabia and the UAE are the economic powerhouses of the region, and together account Energy Economics 59 (2016) 149158 Corresponding author. E-mail addresses: [email protected] (T.N. Atalla), [email protected] (L.C. Hunt). http://dx.doi.org/10.1016/j.eneco.2016.07.027 0140-9883/© 2016 King Abdullah Petroleum Studies and Research Center (KAPSARC). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Contents lists available at ScienceDirect Energy Economics journal homepage: www.elsevier.com/locate/eneeco

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Page 1: Modelling residential electricity demand in the GCC … · Modelling residential electricity demand in the GCC countries Tarek N. Atallaa,⁎,LesterC.Hunta,b a King Abdullah Petroleum

Energy Economics 59 (2016) 149–158

Contents lists available at ScienceDirect

Energy Economics

j ourna l homepage: www.e lsev ie r .com/ locate /eneeco

Modelling residential electricity demand in the GCC countries

Tarek N. Atalla a,⁎, Lester C. Hunt a,ba King Abdullah Petroleum Studies and Research Center (KAPSARC), Riyadh, Saudi Arabiab Surrey Energy Economics Centre (SEEC), University of Surrey, UK

⁎ Corresponding author.E-mail addresses: [email protected] (T.N. Ata

(L.C. Hunt).

http://dx.doi.org/10.1016/j.eneco.2016.07.0270140-9883/© 2016 King Abdullah Petroleum Studies(http://creativecommons.org/licenses/by/4.0/).

a b s t r a c t

a r t i c l e i n f o

Article history:Received 22 December 2015Received in revised form 19 July 2016Accepted 26 July 2016Available online 3 August 2016

JEL classification:C22Q41Q43

This paper aims at understanding the drivers of residential electricity demand in the Gulf Cooperation Councilcountries by applying the structural time seriesmodel. In addition to the economic variables of GDP and real elec-tricity prices, the model accounts for population, weather, and a stochastic underlying energy demand trend as aproxy for efficiency and human behaviour. The resulting income and price elasticities are informative for policymakers given the paucity of previous estimates for a region with particular political structures and economiessubject to large shocks. In particular, the estimates allow for a sound assessment of the impact of energy-related policies suggesting that if policy makers in the region wish to curtail future residential electricity con-sumption they would need to improve the efficiency of appliances and increase energy using awareness of con-sumers, possibly by education and marketing campaigns. Moreover, even if prices were raised the impact oncurbing residential electricity growth in the region is likely to be very small given the low estimated priceelasticities—unless, that is, prices were raised so high that expenditure on electricity becomes such a large pro-portion of income that the price elasticities increase (in absolute terms).© 2016 King Abdullah Petroleum Studies and Research Center (KAPSARC). Published by Elsevier B.V. This is an

open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Keywords:GCC residential electricity demandStructural time series modelImpact of weather and exogenous underlyingenergy demand trend (UEDT)

1. Introduction

In aworldwith increased international focus on energy use, compar-ing energy demand behaviour across countries can inform decisionmakers about their country's relative performance and opportunitiesfor future improvement. In particular, understanding the drivers ofresidential electricity demand—and by association the intensity andproductivity of residential electricity use—has become increasingly im-portant for policy-related international cross-country comparisons.However, the contrasts are arguably more meaningful when compari-sons are normalized for uncontrollable exogenous factors, weatherbeing a prime example. Given the rapid development of electricityusing appliances (such as air conditioners), the interdependencybetween climate variation and residential electricity consumption has,in all probability, increased—with space heating and cooling representingthe largest share of building energy consumption in many countries(Pérez-Lombard et al., 2008). Moreover, analysing the effect of weatheron residential electricity demand is of special relevance to the GulfCooperation Council (GCC) countries—Bahrain, Kuwait, Oman, Qatar,Saudi Arabia, and the United Arab Emirates (UEA)—which, by virtue ofbeing located near the tropics, are characterized by one of the hottestand most arid climates in the world.

Furthermore, residential electricity consumption in the GCC coun-tries has increased rapidly over recent decades amid a steep increase

lla), [email protected]

and Research Center (KAPSARC).

in population and relatively fast economic growth (Squalli, 2007;Reiche, 2010). This was at a time when residential electricity prices inthe GCC were administered by member countries and, as such, fixedin nominal terms for a number of years between adjustments. Withinthis context, this paper attempts to model residential electricitydemand for the six GCC countries in order to estimate the income,price, and population elasticities as well as controlling for the effect ofclimate conditions. The model utilized recognizes that electricity is aderived demand based on the demand for energy services such asheating, cooling, and cooking (Hunt and Ryan, 2015). Hence, in additionto the key drivers of income, prices, population, andweather, an explicitallowance is made for energy efficiency and other exogenous effects byestimating a stochastic underlying energy demand trend, as suggestedby Hunt et al. (2003a, 2003b).

This paper is divided into five sections as follows: after theIntroduction, Section 2 discusses the background to the work andrelevant previous literature, Section 3 details themethodology adopted,Section 4 discusses the data and estimation results, and Section 5 closeswith a summary and conclusion.

2. Background

2.1. Residential electricity in the GCC countries

Despite sharing many common traits, the GCC economies are not asmacro-economically unified as might be assumed. Saudi Arabia and theUAE are the economic powerhouses of the region, and together account

Published by Elsevier B.V. This is an open access article under the CC BY license

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Fig. 1.Map of the GCC countries showing the GDP per capita in 2010 US $.(Source: World Bank, 2014).

1 In addition, Abdel-Aal et al. (1997) developed an ARIMA model for the Eastern prov-ince of Saudi Arabia in order to forecast monthly electricity consumption for the region.

150 T.N. Atalla, L.C. Hunt / Energy Economics 59 (2016) 149–158

for around 70% of its Gross Domestic Product (GDP) and 80% of itspopulation (World Bank, 2014). However, when comparing GDP percapita of the GCC countries in 2010 another picture emerges; at currentvalues, Qatar, Kuwait and the UAE stand at about two to four times thevalues of the remaining countries as illustrated in Fig. 1, which for theirpart are still more than double the world average (World Bank, 2014).

Over the past three decades, the GCC governments invested a largepart of their oil and gas rents in infrastructure development, drasticallyincreasing the electrification rate in cities and villages across the region(Squalli, 2007). This has been associated with residential electricityconsumption increasing rapidly in each country, as shown in Fig. 2.Related to this is the energy pricing regime in the GCC region, wheremost power generation is undertaken using locally available hydrocar-bon resources, whichhas resulted in nominal electricity prices tradition-ally being administrated by government bodies—set intermittently as aresult of policy changes with little, or no, connection to internationalcommodity markets.

The different pricingmechanisms in the GCC countries have resultedin varying levels of subsidies. Residential electricity retail prices in 2005shown in Fig. 3 illustrate the large variation between Bahrain and theUAE, which were more than five times the price in Kuwait and SaudiArabia. Still, when compared internationally, GCC electricity prices area fraction of that in the European Union and the United States. All ofwhich has probably contributed to the disproportionate residentialenergy consumption per capita across the GCCwhere it is sizably higherthan the OECD, China and the World average, as shown in Fig. 4.

2.2. Previous GCC residential electricity demand modelling

As far as is known, there are very few published studies attemptingto model residential electricity demand for the GCC countries, asshown in Table 1. The studies that have been published can be catego-rized into two groups: one that has attempted to model the GCCcountries together in a panel context and another that have attempted

to model the countries individually (either in a one-country study ormulti-country study).1 Of those studies, it can be seen that the earlierones by Eltony and associates for Kuwait produced relatively smallestimated income and price elasticities. Whereas the more recentmulti-country studies published in the 2000s suggest rather largeestimated income and price elasticities—the latter being somewhatlarger (in absolute terms) than might be expected for countries withthe characteristics outlined above. Hence, the research undertakenhere attempts to re-evaluate these elasticities using a framework thatis believed to bemore appropriate for such energy economies, as brieflydiscussed in the next sub-section.

2.3. Modelling approach

There are many examples of modelling the demand for aggregateand individual energy sources in the energy economics literature thatinvolve a range of different specifications and methodologies. This isparticularly true for countries from the developed world but, asillustrated above, this is not the case for residential electricity demandin the GCC countries. Possible reasons for the paucity of past studiesfor the GCC countries could be the difficulty in modelling sectors incountries with administered nominal prices that change periodicallyas well as being volatile in the face of a number of economic and geopo-litical shocks that occurred during the estimation period.

One approach used to model energy demand is the Structural TimeSeries Model (STSM) introduced by Harvey et al. (1986), Harvey(1989), Harvey and Shephard (1993), Harvey and Scott (1994) andHarvey (1997). This, unobserved components model, allows for theestimation of an exogenous stochastic trend that Hunt et al. (2003a,2003b) refer to as the Underlying Energy Demand Trend (UEDT).Furthermore, this approach is consistent with Hunt and Ryan (2015)

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Fig. 2. Residential electricity consumption (ktoe) for the GCC countries from 1985 to 2012. (Saudi Arabia is on the right hand side vertical axis.)(Source: IEA, 2014).

151T.N. Atalla, L.C. Hunt / Energy Economics 59 (2016) 149–158

who show that when a model of energy demand is based upon the de-mand for the energy services that are produced with appliances,then there should be an allowance for the efficiency of the appliances,separate from the price driver.

The use of the STSM/UEDT approach is increasingly used to modelenergy demand; see for example, Ackah (2014), Adeyemi et al.(2010), Adeyemi and Hunt (2014), Broadstock and Hunt (2010),Broadstock and Papathanasopoulou (2015), Dilaver et al. (2014),Dilaver and Hunt (2011a, 2011b, 2011c), Dimitropoulos et al. (2005),Hunt et al. (2003a, 2003b), Hunt and Ninomiya (2003, 2005), Javidand Qayyum (2014), and Sa'ad (2009, 2011). These cover a range ofcountries, sectors, and fuels; however, as far as is known, this approachhas not been applied to the GCC countries.

Therefore, following Hunt et al. (2003a, 2003b), the general modeloutlined in Section 3 below includes the key drivers of income, prices,population, andweather (discussed further below) as well as a stochas-tic UEDT. The UEDT is included to allow for exogenous changes in theuse of residential electricity that come from energy efficiency

Fig. 3. Comparative prices of residential electricity in 2005 (2010$ per toe).(Source: Enerdata, 2015; World Bank, 2014.)

improvements and other exogenous effects such as changes in tastes,behaviour, and legislation. Moreover, the STSM/UEDT approach allowsfor the inclusion of interventions that take account of the impact onthe UEDT from one-off impacts and/or from structural breaks broughtabout by key events such as wars—which, is particularly relevant tothe countries being studied. Thus, given the nature of the data beingmodelled, the instability of the region and the pricing regimes, thisapproach is seen as being particularly relevant to model the GCCcountries' residential electricity demand—as well as being consistentwith the Hunt and Ryan (2015) energy services derivation. Further-more, given the extreme climatic situation in the Gulf countries theimpact of weather is explicitly considered; briefly discussed in thenext sub-section.2

2.4. Previous modelling of weather effects in electricity demand modelling

Several researchers have analysed the effect of weather on energyconsumption. For the United States, Rosenthal et al. (1995) estimatedthe effect of global warming on residential and commercial spaceheating requirements. Davis et al. (2003) applied Divisia decompositionand regression analysis to investigate the effect of weather and energymix on the variation of energy and carbon intensity. Using the heatingand cooling degree-days methodology, Davis et al. (2003) found thatbetter weather conditions accounted for around 30% of the reductionin energy consumption in the residential, commercial, and industrialsectors. Amato et al. (2005) analysed the implications of climate change

2 It is worth emphasizing that the attempt here is to understand past electricity con-sumption behaviour in the GCC countries, thus providing policymakers (such as the SaudiEnergy Efficiency Center) and state-owned electricity companies (such as the Saudi Elec-tricity company) with useful information about residential electricity demand elasticities.The aim is therefore not to explicitly provide models for forecasting given that the GCCcountries are still developing and there are likely to be significant changes over the nextcouple of decades. However, the information supplied by this research should aid policymakers as they navigate their way through the difficult decisions they will have to makeover the coming years. That said as Hunt andNinomiya (2003; p. 69) argue, an “advantageof using the STSMto estimate energy demandmodels is in forecasting, at least in the short-term”. They argue that that a more conventional linear deterministic trendmodel is likelyto lead to misleading short-term forecasts if the ‘true’ UEDT is non-linear whereas theSTSM puts more weight on the most recent observations. Therefore, arguably the STSMismore applicable for forecasting the near future—which is particularly relevant to the rel-atively volatile GCC countries.

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Fig. 4. Comparative size of per capita residential electricity consumption in 2010.(Source: IEA, 2014).

152 T.N. Atalla, L.C. Hunt / Energy Economics 59 (2016) 149–158

for residential and commercial energy demand in the Commonwealthof Massachusetts using a two-step estimation procedure that incorpo-rates region-specific climatic variables, infrastructure, socioeconomic,and energy use profiles. Their results show that after controlling forsocioeconomic factors, the variation in degree-days does explainhistorical changes in demand. Olonscheck et al. (2011) replicated thesame analysis for Germany.

Elkhafif (1996) developed an iterative econometric technique,which he applied to correct energy demand for abnormal weatherconditions for the Canadian province of Ontario. He found that residen-tial and commercial natural gas data require more weather correction

Table 1Previous GCC electricity demand studies.

Name Data type Countries LR Incomeelasticity

LR pricelastic

Eltony andMohammad (1993) Panel of countries GCC 0.20 −0.14

Eltony (1995) Time series Kuwait 0.09 −0.06

Eltony and Hosque (1996) Time series Kuwait 0.65 −1.97

Diabi (1998) Panel of regions Saudi Arabia 0.09 to 0.49 0.01 to

Al-Faris (2002) Time series Saudi Arabia 1.65 −1.24UAE 2.52 −2.43Kuwait 0.33 −1.10Oman 0.29 −0.82Bahrain 5.39 −3.39Qatar 2.65 −1.09

Eltony and Al-Awadhi (2007) Time series Kuwait 0.31 −0.56Squalli (2007) Time series OPEC

CountriesN/A N/A

Narayan and Smyth (2009) Panel Kuwait 1.32 N/AOman 3.86 N/ASaudi Arabia 3.07 N/A

than the data for the industrial sector,meaning a lower effect ofweatheron the latter. More recently, De Cian et al. (2013) studied the relation-ship between residential energy demand and temperature on a globallevel by estimating short- and long-run demand elasticities usingpanel co-integration analysis and used the estimates to project changesin energy demand due to temperature increases.

Eskeland and Mideksa (2009) applied panel analysis to study theeffect of weather on electricity consumption based on a 10-year paneldata set for 30 European countries and found that random weathervariations have a statistically significant impact on residential electricitydemand and concluded that future climate change may lead to a

eity

Notes

Models estimated for the residential, commercial, and industrial sectors.Residential electricity demand elasticity estimates shown.Models estimated for the residential, commercial, and industrial sectors.Residential electricity demand elasticity estimates shownModels estimated for the residential, commercial, and industrial sectors.However, results suggest that no long run cointegrating relationship existsfor the residential sector so no results are available for the residential sector.Total electricity demand elasticity estimates shown.

−0.14 Various panel models estimated for regional total electricity demand. Therange for total electricity demand elasticity estimates shown.Total electricity demand elasticity estimates shown.

Focusses on Granger causality for total electricity demand. Therefore, noelasticity estimates are shown.Focusses on Granger Causality for total electricity and excludes electricityprices from the analysis. Therefore, only of income elasticities of totalelectricity demand estimates are shown.

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153T.N. Atalla, L.C. Hunt / Energy Economics 59 (2016) 149–158

reduction in European energy demand. In addition, Bigano et al. (2006)analysed the temperature effect for different energy sectors for differentfinal users of OECD countries using a dynamic panel analysis that incor-porates the demand for coal, gas, electricity, and oil derivatives forhouseholds and industrial uses. Bigano et al.’s (2006) results suggestthat industrial demand is insensitive to climate changewhile residentialdemand responds negatively to variations. Furthermore, Christensonet al. (2006) estimated the impact of climate warming on the Swissresidential sector based on the building stock using monthly degree-days data for the period 1901–2003 finding a 11% to 18% decrease indegree days, with the results used to develop scenario calculations offuture energy demand that reflect future decreases due to buildingretrofit. In summary, a number of past energy demand studies haveattempted to include weather effects and have shown that generallytheir inclusion is important. However, there is little of evidence of theimpact of weather for the GCC countries, so it is worth attempting todiscover the outcome from the inclusion of appropriate weathervariables in energy demand models for the countries in the region.

The discussion in this section highlighted the particular characteris-tics of the GCC countries and challenges this provides for modellingresidential electricity demand. It has also introduced, what is believedto be, an appropriate method suitable for such a task and discussedthe importance of the weather variables and an exogenous stochasticUEDT. The next section, therefore, details this methodology, explainingthe adopted estimation strategy.

3. Methodology

Given the above discussion, it is assumed that generally each GCCcountry's residential electricity demand is identified by:

Et ¼ f Yt ; Pt ; POPt ;HDDt ;CDDt ;UEDTtð Þ ð1Þ

where;

Et Residential electricity demand;Yt Real GDP3;Pt Real residential electricity price;POPt Population;HDDt Heating degree-days;CDDt Cooling degree-days; andUEDTt Underlying Energy Demand Trend.

Eq. (1) is estimated using a dynamic autoregressive distributed lagspecification as follows:

et ¼ α1et−1 þ α2et−2 þ γ0yt þ γ1yt−1 þ γ2yt−2 þ δ0pt þ δ1pt−1

þδ2pt−2 þ θ0popt þ θ1popt−1 þ θ2popt−2 þ λ0hddt þ φ0cddtþUEDTt þ εt ð2Þ4

where et, yt, pt, popt, hddt, and cddt are the natural logarithms of Et, Yt,Pt, POPt, HDDt, and CDDt in year t respectively and εt is a randomwhite noise error term. The coefficients γ0, δ0, θ0, λ0, and φ0 thereforerepresent the short-run impact elasticities for income, prices,population, heating degree-days and cooling-degree-days respectively

3 Given the residential sector is the focus then ideally the income driver should behousehold, ormaybepersonal, income. However, it is difficult to get such consistent annu-al data for all sixGCC countries over thewhole of the estimation period; hence,GDP is usedhere as a proxy for the income driver similar to some previous researchers; such as,Narayan et al. (2007)—who estimated short- and long-run elasticities for the G7 econo-mies using panel co-integration. That said GDP normally correlates very closely withhousehold or personal income although it is recognized that for the GCC countries GDPis very much related to oil prices.

4 A two-year lag is chosen to capture any possible dynamic effects, since it is seen as areasonable length of time given the data set used.

and the long-run income, price, and population elasticities are givenby Γ ¼ γoþγ1þγ2

1−α1−α2, Δ ¼ δoþδ1þδ2

1−α1−α2, and Θ ¼ θoþθ1þθ2

1−α1−α2respectively.

Furthermore, the UEDT is a stochastic trend estimated using theSTSM as follows:

μ t ¼ μ t−1 þ βt−1 þ ηt ; ηt � NID 0;σ2η

� �ð3Þ

βt ¼ βt−1 þ ξt ; ξt � NID 0;σ2ξ

� �ð4Þ

where μt and βt are the level and slope of the UEDT respectively. ηt andξt are the mutually uncorrelated white noise disturbances withzero means and variances ση

2 and σξ2 respectively (known as hyper-

parameters). The disturbance terms ηt and ξt determine the shape ofthe stochastic trend component (Harvey and Shephard, 1993). Wherenecessary irregular or outlier interventions (Irr), level interventions(Lvl) and slope interventions (Slp) are added to the model to aid thefit and help ensure the model passes the diagnostic tests for the stan-dard residuals and the auxiliary (irregular, level and slope) residuals.Moreover, the interventions provide information about importantbreaks and structural changes during the estimation period (Harveyand Koopman, 1992) and, according to Dilaver and Hunt (2011a), inthe presence of such interventions the UEDT can be identified as:

UEDTt ¼ μ t þ irregular interventionsþ level interventionsþ slope interventions ð5Þ

The modelling strategy involves estimating Eqs. (2)–(4) by acombination of maximum likelihood and the Kalman filter and theneliminating insignificant variables and adding interventions but ensur-ing the model passes an array of diagnostic tests5 until the preferredparsimonious model is obtained. The software package STAMP 8.10(Koopman et al., 2007) is used for the estimation of themodel discussedin the results section below.

4. Data and estimation results

4.1. Data

Data for this research was gathered from a number of sources.Residential electricity consumption for the six countries was obtainedthrough the IEA (2014) and World Bank (2014). Time series for realand nominal GDP and population were obtained from World Bank(2014). Cooling degree-days and heating degree-days were takenfrom the CMCC-KAPSARC database (Atallah et al., 2015) for Kuwait,Oman, Saudi Arabia, and United Arab Emirates. The specific degree-days time-series were generated from the temperature-based indexwith a reference temperature of 21.1 °C for cooling and 18.3 °C forheating and as such, it does not account for the effects of humidity orsolar radiation.6 As the above-mentioned database does not includecooling degree-days and heating degree-days data for Qatar andBahrain, these were instead computed using Wolfram Alpha's (n.d.)engine. Unlike the data from the CMCC-KAPSARC database, no popula-tion weighting was necessary for the Wolfram Alpha degree-dayssince Qatar and Bahrain have relatively small area sizes, which makesthe weather conditions relatively homogenous across all their cities.7

The real residential electricity prices were generated from differentsources. Kuwait's nominal prices were obtained from Fattouh andMahadeva (2014) and transformed into real 2005$ per toe. Data forBahrain was constructed from Akbari et al. (1996) and Al-Faris (2002)

5 With 10% normally being themaximum level to reject that the null hypothesis for in-dividual parameter coefficients, interventions, and diagnostic tests.

6 The literature does not give a clear direction concerning reference temperatures to usefor heating degree-days and cooling degree-days; however, those chosen are believed tobe the most appropriate for the behaviour of consumers in the GCC region.

7 See the on-line Appendix for further discussion of the weather data used in theestimation.

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154 T.N. Atalla, L.C. Hunt / Energy Economics 59 (2016) 149–158

and completed by recent years' prices from the Kingdom of BahrainiEnergy and Water Authority (2015) and successive statistical bulletinsof the Arab Union of Electricity (n.d.). Saudi Arabia's residentialelectricity prices were obtained from the Electricity and Co-generationRegulation Authority (ECRA, n.d.) while Omani prices were gatheredfrom Al-Faris (2002), El-Katiri (2011), the Omani Chamber ofCommerce and Industry (2015) and IRENA (2014). Prices for theUnited Arab Emirates and Qatar were generated based on data fromAl-Faris (2002), various ministerial decrees and successive statisticalbulletins of the Arab Union of Electricity (2012). Although very limitedin occurrence, missing yearly data was interpolated or assumedconstant. When applicable, various data was corroborated with theinformation provided by Enerdata (2015).

4.2. Results

Following the estimation strategy outlined in the methodologysection above, the preferred models for each country are shown inTable 2 along with an array of diagnostic tests. Table 2 also shows thatthe preferred models for all countries pass almost all the diagnostictests including the additional normality tests for the auxiliary residualsgenerated by the STSM approach. However, the results for the individualcountries differ considerably; consequently, each country is discussed indetail below.Nonetheless, it should benoted that bothQatar and theUAEwere difficult countries tomodel and for both countries the original gen-eral Eq. (2) above was replaced by a per capita specification as explainedfurther below.8 Hence, Bahrain, Kuwait, Oman, and Saudi Arabia arediscussed first followed by the discussion on Qatar and the UAE.9

4.2.1. BahrainThe preferred model for Bahrain passes all the diagnostic tests with

dynamic terms limited to the second lag of GDPwith no role for the realelectricity price nor population. Thus, the estimated short-run (impact)income, price, and population elasticities are all zero (i.e. they are allperfectly inelastic in the short run) but in the long run the estimatedincome elasticity is 0.71 (i.e. it is inelastic) whereas the estimatedlong-run price and population elasticities are zero (i.e. they are alsoperfectly inelastic in the long run). Arguably, the zero price elasticity isnot unexpected given the historical low cost of electricity whencompared with household income; although, it was expected thatpopulation would have a greater impact. For weather, only the coolingdegree-days variable is significant with an estimated impact elasticityof−0.66. This is in linewith prevailingweather conditions, as the coun-try is one of the hottest in the world with consistently high CDD values.By contrast, Bahrain's HDD values are very low and are not likely to playany role in shaping the electricity demand due to space conditioning.

During the estimation process, an irregular intervention for 1991and a level intervention for 1998 were added to ensure that the fullarray of diagnostic tests were passed; thus even though the 1998intervention is only significant at the 12% level it was maintained.These interventions probably reflect two major international events.In 1991, the first Gulf War was at its peak with Bahrain's economyparticularly affected due to its proximity to the war zone in the ArabGulf. The second intervention pertaining to 1998 is probably a repercus-sion of the Asian Financial Crisis of 1997 and the drastic reduction inoil price that ensued given the Bahraini economy was still sizablydependent on oil rents, which shrank notably (and the estimatedincome elasticity is unlikely to pick up adequately this effect). Theresultant estimated UEDT illustrated in Fig. 5a is generally upwardsloping (after allowing for the sharp reduction in 1991 caused by the1991 intervention) suggesting generally exogenous electricity usingbehaviour.

8 Moreover, as explained below, some difficulties still arose—especially for the UAE.9 See the on-line Appendix for a discussion of the impact of omitting the weather

variables from the preferred models for Bahrain, Kuwait, Oman, and Saudi Arabia.

4.2.2. KuwaitGiven the estimation period covers the build up to, and the period of,

the Gulf War in 1990–1991, not surprisingly the preferred model forKuwait required the inclusion of interventions around that period—alevel intervention in 1991 and another in 1992. In all probability,reflecting the invasion of Kuwait by Iraq, leading to a mass exodus ofits population and long-lasting damage to its infrastructure. The levelintervention in 1991 at the height of the war suggests a notable exoge-nous reduction in electricity demand followed by an over compensatingrecovery in 1992—which is illustrated in the estimated UEDT shown inFig. 5b. Thus in the period leading up to 1991 and after 1992 untilabout 2000 the estimated UEDT falls slightly suggesting exogenouselectricity saving behaviour during these periods whereas after 2000the estimated UEDT rises suggesting exogenous electricity using behav-iour during this period.

The resultant preferred model includes the CDD variable despitebeing only statistically significant at 20% since it was retained to ensurethat all the diagnostic tests were passed. Kuwait traditionally has quiteharsh weather conditions in the summer with little year-to-yearvariation so unsurprisingly it was not possible to find the HDD variablesignificant at the required level. However, no real electricity price termsare included in the preferred model with dynamic terms limited to thefirst lag of GDP and population. This gives estimated short-run (impact)income and population elasticities of 0.30 and 0.29, respectively andestimated long-run income and population elasticities of 0.43 and0.68, respectively (i.e. although larger in the long run both income andpopulation are inelastic in the long run). For the real electricity price,however, both the short-run and the long-run elasticities are estimatedto be zero (suggesting that Kuwait's residential electricity demand isperfectly price inelastic in both the short and long run).

4.2.3. OmanThe Omani preferred model again passes all the diagnostic tests and

includes a lagged dependent variable and contemporaneous terms forincome, price and the CDD variable—but no role is found for population.This gives estimated short-run (impact) income and price elasticities of0.72 and−0.09, respectively and estimated long-run income and priceelasticities of 0.86 and −0.10, respectively (i.e. the long run estimatedelasticities are slightly larger—in absolute terms—in the long run butsuggests that Omani residential electricity demand is inelastic in boththe short and long run).

For Oman, three level interventions were found to be necessary, andsignificant, during the estimation process; 1986, 1993, and 1996, whichprobably reflects the reduced income from oil rents that was character-istic of the mid-1980s oil glut and changes in pricing mechanisms for1993 and 1996. The estimated UEDT from the process is deterministicbut is ‘non-linear’ given the three level interventions, as illustrated inFig. 5c. Nonetheless, the estimated Omani UEDT is generally increasingthroughout the estimation period, suggesting exogenous electricityusing behaviour.

4.2.4. Saudi ArabiaThepreferredmodel for Saudi Arabia passes almost all the diagnostic

tests, the one slight issue being the first order autocorrelationcoefficient; however, the Durbin–Watson statistic for first order serialcorrelation suggests that this is not necessarily a problem and theBox–Ljung test suggests that general serial correlation is not a problem.The preferred model, therefore, includes contemporaneous terms forthe real electricity price and population but not for GDP; however, itdoes include one-year lagged terms for GDP and population. This resultsin estimated short-run and long-run incomeelasticities of zero and0.48,respectively—suggesting that Saudi Arabia's residential electricitydemand is perfectly income inelastic in the short run but relativelyinelastic after a year and in the long run. For the real electricity price,however, the estimated short-run and long-run elasticities are both−0.16—suggesting that Saudi Arabia's residential electricity demand

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Table 2Preferred GCC residential energy demand models.

Bahrain Kuwait Oman Saudi Arabia Qatar UAE

Estimated Coefficientsα1 – – 0.1655* – 0.5660*** –γ0 – 0.2988*** 0.7198*** – – –γ1 – 0.1271** – 0.4801*** – –γ2 0.7130*** – – – – –δ0 – – – −0.1597** – –δ1 – – −0.0831** – – –θ099−12 n/a n/a n/a n/a −0.0276* n/aθ003−12 n/a n/a n/a n/a n/a 0.0072***θ0 – – – 4.2004*** 1.0000## −0.1165***θ1 – 0.3869*** – −3.4003*** −0.5660*** 0.1165***θ2 – 0.2887*** – – – –λ0 0.6649*** 0.1806 0.4829** 0.5034*** 0.5752 –φ0 – – – 0.1624*** –

LR elasticity estimatesΓ (GDP) 0.71 0.43 0.86 0.48 0.00 0.00Δ (Price) 0.00 0.00 −0.10 −0.16 0.00 0.00Θ (Pop) 0.00 0.68 0.00 0.80 1.00 0.00Θ99−12 (Pop 1999–2012) n/a n/a n/a n/a 0.94 n/aΘ03−12 (Pop 2003–2012) n/a n/a n/a n/a n/a 0.01

HyperparametersIrregular 0.000000 0.000419 0.000476 0.000227 0.000000 0.000287Level 0.001144 0.000197 0.000000 0.000000 0.008425 0.000000Slope 0.000000 – 0.000001 0.000040 0.000000 0.000000

Interventions Irr1991*** Lvl1991*** Lvl1986*** Lvl1991* Lvl1989*** Lvl1993***Lvl1998 Lvl1992*** Lvl1993** Irr1993**

Lvl1996*** Irr2005***Goodness of fit

p.e.v. 0.000899 0.000586 0.000451 0.000392 0.006019 0.000230AIC −6.514 −6.799 −6.990 −7.129 −4.470 −7.898R2 0.997 0.997 0.999 0.999 0.951 0.965Rd2 0.916 0.977 0.881 0.766 0.768 0.832

Residual DiagnosticsStd Error 0.030 0.024 0.021 0.020 0.076 0.015Normality 0.10 0.72 1.64 0.58 2.04 0.41H(h) H(7) = 2.55 H(6) = 0.82 H(6) = 0.25 H(6) = 0.85 H(6) = 0.86 H(6) = 1.57r(1) 0.14 0.11 −0.02 −0.33* −0.06 −0.04DW 1.71 1.75 1.71 2.27 2.07 1.81Q(p, d) χ3

2 = 1.76 χ42 = 5.84 χ3

2 = 2.86 χ32 = 5.13 χ3

2 = 1.17 χ32 = 0.81

Auxiliary residuals:Normality—Irregular 2.55 1.36 0.87 1.11 0.24 0.28Normality—Level 0.85 0.51 0.10 0.24 3.25 2.72Normality—Slope 3.69 - 2.37 1.99 1.36 0.93

Pred. Failure χf2 χ32 = 0.23 χ3

2 = 2.43 χ32 = 0.83 χ3

2 = 2.64 χ32 = 0.71 χ3

2 = 6.46*

Notes for Table 1:(i) All estimated preferred models and tests obtained from the software package STAMP 8.10 (Koopman et al., 2007);(ii) The estimation period is 1985 to 2012, other than for Kuwait which is for 1985 to 2009;(iii) the estimated preferred models for Bahrain, Kuwait, Oman, and Saudi Arabia were estimated were obtained after testing down from Eq. (2) as explained in the methodology

section, whereas the preferred models for Qatar and the UAE were obtained from a restricted per-capita version of Eq. (2) as explained in the results section (and Footnote 9).(iv) ***, **, & * denotes statistical significance at 1%, 5% and 10% respectively;(v) ## represents a constrained estimate;(vi) Given the second lag of residential electricity demand, and the second lag of the reel electricity price was omitted for every country during the estimation process, the rows for α2

and δ2 are omitted from the table.(vii) p.e.v. is the prediction error variance and AIC the Akaike information criterion;(viii) R2 is the coefficient of determination and Rd

2 is the coefficient of determination based on differences;(ix) Normality is the Bowman-Shenton test; approximately distributed as χ2

2;(x) H(h) is the test for heteroscedasticity, distributed approximately as F(h,h);(xi) r(1) is the residual autocorrelations at lag 1 distributed approximately as N(0, 1/T);(xii) DW is the Durbin-Watson statistic;(xiii) Q(p,d) is the Box-Ljung statistic based on the first p residuals autocorrelations and distributed approximately as χd

2; and(xiv) Pred. Failure χf

2 is the predictive failure test for the last three years of the estimation period distributed approximately as χ32.

155T.N. Atalla, L.C. Hunt / Energy Economics 59 (2016) 149–158

is relatively price inelastic in both the short and long run. For populationthe preferred equation suggests that the short-run (impact) effect isvery large with the estimated elasticity being 4.20, however this isdampened in the long run given the estimated long-run populationelasticity is 0.80. A probable reason is that Saudi Arabia has a large expa-triate population (around 30% of total population) that has a fluctuatingsize and purchasing power over the years.Many in the expatriate labourforce are low-wage workers with short-term and project specific con-tracts. For weather, Saudi Arabia is the only GCC country where boththe cooling and heating degree-day variables were found to be signifi-cant and therefore retained in the preferred model. This is in line with

expectations as Saudi Arabia has a much larger diverse geographythan its GCCneighbours. The northern and southern parts of the countryhave a mountainous topography that yields lower temperatures andthus result in higher heating degree-days values. Still, the estimated im-pact of CDD is somewhat higher than that for HDD.

For Saudi Arabia, a level intervention for 1991 is included in thepreferred model, which probably reflects, as for Kuwait, the spill overeffects of the first Gulf War (1990–1991). Despite this, the estimatedUEDT illustrated in Fig. 5d is generally rising over the estimation periodsuggesting exogenous electricity using behaviour—i.e. either there havebeen no, or very little, electricity efficiency improvements over the

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Fig. 5. Estimated Underlying Energy Demand Trends (UEDTs).

156 T.N. Atalla, L.C. Hunt / Energy Economics 59 (2016) 149–158

period, or if there were, then they have been more than outweighed byelectricity using behavioural changes.

4.2.5. Qatar and UAEModelling for Qatar and theUAE proved to be somewhat problemat-

ical because it was impossible to find preferred models that pass all thediagnostic tests with GDP, the real price of electricity, and populationbeing individually statistically significant. Consequently, electricity percapita models were estimated instead10; nonetheless, for the UEAthe sample period was also curtailed to 1985 to 2009 since it proved

10 This involved omitting yt and popt from the right hand side of Eq. (2), replacing themby the natural logarithm of Yt/POPt, and replacing et by the by the natural logarithm of Et/POPt on the left hand side of Eq. (2).

impossible to find a statistically acceptable model for the whole periodup to 2012 and even then, the preferred model failed the predictivefailure test at the 10% level.

When testing down using the per capita models, it was not possibleto find a role for GDP. In addition, the real electricity price variable wasexcluded for Qatar and only the first difference of the real electricityprice was found to be significant for the UAE. Furthermore, differentialslope dummies were needed for population during certain periods(explained further below). Given this, the preferred model for Qatarshown in Table 211 includes a lagged dependent variable (electricity

11 Note for consistency, the coefficients for Qatar and the UAE presented in Table 1 havebeen re-parametrized to be consistent with Eq. (2) and the estimates for the other GCC re-sults in the table.

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12 It is worth noting that this research is part of a larger research project analysing andunderstanding energy demand in the GCC region. Future work could include analysinggasoline demand in the region, exploring the impact of alternative weather variables suchas humidity, building codes (if appropriate data are available), as well as a regional analy-sis of electricity demand in Saudi Arabia.

157T.N. Atalla, L.C. Hunt / Energy Economics 59 (2016) 149–158

per capita in this case), cooling degree-days (despite only being signifi-cant at the 16% level) and a slope dummy for population covering theperiod 1999–2012, but with a stochastic UEDT (see Fig. 5e and furtherdiscussion below). Whereas for the UAE, the preferred model inTable 2 includes only the change in the real electricity price and aslope dummy for population covering the period 2003–2012, but witha deterministic trend with a large structural break in 1993 (see Fig. 5fand further discussion below).

The estimated Qatar short- and long-run income and price elastici-ties are therefore zero (suggesting that electricity demand is perfectlyincome and price inelastic in both the short and long run). Whereasfor population, the short-run and long-run estimated populationelasticities are unitary for the period 1985 to 1998 but for the period1999 to 2012 falls to 0.94 in the long run. Furthermore, the preferredequation for Qatar includes a level intervention for 1989 and twoirregular interventions, one for 1993 and one for 2005. These probablyreflect the repercussions of the Tankers' War (closing stage of theIran-Iraq war where tankers were targeted and Qatar's offshore fields,mostly shared with Iran, were impacted), electricity price reformin 1993, and a sharp increase in expatriate population starting inmid-2000 that coincided with Qatar's fast-paced economic boom.The resultant estimated UEDT shown in Fig. 5e generally rises duringthe late 1980s until the late 1990s but generally falls thereafter(allowing for the sharp increase in 2005 caused by the irregularintervention)—suggesting generally exogenous electricity savingbehaviour in the 2000s onwards.

The estimated UAE short- and long-run income elasticities are alsozero (again suggesting that electricity demand is perfectly incomeinelastic in both the short and long run).Whereas for the real electricityprice the estimated (impact) short-run elasticity is −0.12 but falls tozero in the long run (i.e. suggesting that Qatar's residential electricitydemand is relatively inelastic in the short run and perfectly inelastic inthe long run). For population, the estimated short- and the long-runpopulation elasticities are zero for the period 1985 to 2002 but for theperiod 2003 to 2012 the inclusion of the slope dummy suggests a slightincrease to 0.01—so effectively almost perfectly inelastic with respect topopulation in both the short and the long run. Furthermore, thepreferred equation for the UAE includes a level intervention for1993, which could reflect the sudden change in the electricity pricingmechanism that occurred in that year—especially given the actual realelectricity price variable was never significant and therefore omittedfrom the analysis. The resulting estimated UEDT shown in Fig. 5f isdeterministic and is clearly generally falling (after allowing for thesharp increase in 1993 caused by the level intervention)—suggestinggenerally exogenous electricity saving behaviour from the mid-1990sonwards.

5. Summary and conclusion

This paper has attempted to estimate residential electricity demandfunctions for the six GCC countries with particular characteristics, thusmaking such modelling a challenge—hence, the particular estimationtechnique chosen. The results suggest that by using the STSM goodstatistical results can be found for Bahrain, Kuwait, Oman, and SaudiArabia whereas for Qatar and the UAE this is not necessarily the case(the UAE being particularly problematical).

Focusing on Bahrain, Kuwait, Oman, and Saudi Arabia, the estimatedlong-run incomeelasticities range from0.43 to 0.71. These estimates aregenerally lower than the estimates from papers published since thestart of the 21st century, such as the Al-Faris (2002), Eltony and Al-Awadhi (2007), and Narayan and Smyth (2009)wheremore traditionaleconometric methodologies were applied, which do not allow for theimpact of an exogenous stochastic UEDT norweather. Long-run popula-tion elasticities are also estimated, but found to be zero for Bahrain andOman, but 0.68 and 0.80 for Kuwait and Saudi Arabia, respectively.Moreover, for all the countries' residential electricity demand is found

to be very price inelastic with the estimated long-run price elasticitiesranging from −0.16 to zero, which are somewhat lower (in absoluteterms) than the estimates by Al-Faris (2002). Concerning weather, inthe form of cooling degree-days, the influence on residential electricitydemand in Bahrain, Kuwait, Oman, and Saudi Arabia is generallyinelastic with the estimated impact elasticities found to range from 0.2to 0.7. Furthermore, the UEDTs are found to vary across the four coun-tries but with all of them generally showing exogenous electricityusing behaviour.

Unlike a number of previous attempts to model GCC residentialelectricity demand, the results obtained here use a novel approachthat provides policymakers in the region with valuable and quantifiableinformation. Not only do they provide vital elasticity estimates, theyalso provide information on the separate exogenous behaviouralaspects, which interestingly for Bahrain, Kuwait, Oman, and SaudiArabia generally suggest electricity using behaviour over the estimationperiod.12 Thus given the current pricing regime residential electricityconsumption in these countries is likely to continue to increase apaceas GDP grows and the exogenous electricity using behaviour continues.This suggests that if the policy makers in the region wish to curtailfuture residential electricity consumption they would need to improvethe efficiency of appliances and increase energy using awareness ofconsumers, possibly by education andmarketing campaigns. Moreover,even if prices were raised the impact on curbing residential electricitygrowth in the region is likely to be very small given the low estimatedprice elasticities—unless, that is, prices were raised so high thatexpenditure on electricity becomes such a large proportion of incomethat the price elasticities increase (in absolute terms).

Acknowledgments

An earlier version of this paper was presented and discussed at the33rd USAEE/IAEE North American Conference in Pittsburgh, 2015 andwe are grateful to participants for their comments and suggestions.We are also grateful to two anonymous referees for their commentsand suggestions that have helped to improve considerably the paper;nonetheless, we are of course responsible for all errors and omissions.Furthermore, the views expressed in this paper are those of the authorsand do not necessarily represent the views of their affiliated institutions.

Appendix. Supplementary data

Further discussion of the weather data and the results as well as thedata used for the estimation of themodels in this article can be found inthe online version, at http://dx.doi.org/10.1016/j.eneco.2016.07.027.

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