Credit Spreads on Sovereign Debt
An Explanatory Regression Model & Trading Strategy
Submitted byVaswar Mitra, Vinaya Jain
May 5th, 2006
Independent Study Project under Prof. Campbell Harvey, Term 4 2006
2
Agenda Summary Findings The Origins & Evolution of Sovereign Debt Factors that influence sovereign credit spreads Overview of Methodologies Overview of Regression Analysis Model 1: WB Annual
Regression Model & Trading Strategy Model 2: WB Monthly
Regression Model & Trading Strategies Model 3: ICRG Monthly
Regression Model & Trading Strategies Model 4: Lagged Spreads
Regression Model & Trading Strategy Momentum Trading Strategy Issues to be Explored Further Bibliography
3
Summary Findings WB Data annual and monthly (Annual independent variables
replicated to give monthly data) data gave us high R-Squares in the 85% range
The ICRG monthly data gave us R-Squares in the 63% range, lower than what we got using WB data.
An explanatory model using lagged spreads gave us extremely high R-Squares over 96% even though the residuals were not distributed normally
Long-Only trading strategies using 1-year lags gave us good results, both with WB data and ICRG data. The Long-Short strategy did not work similarly well
Given the high R-Squares using lagged spreads, we felt that a momentum strategy should work well. Our strategy yielded a percent accuracy of only 49% and cannot be used in its current form
4
The Origins of Sovereign Debt The first public bonds originated in 17th century European city-states –
lifetime/redeemable annuities that paid interest to bondholders. The UK “Consol” (1751) is the earliest example of a government bond used to
supplement revenues from taxation Liquid, perpetual (redeemable at par) and highly credible. Backed by sinking funds,
Consol’s formed 96% of Britain’s total debt from 1801-1914 The Bank of England (1694) was mandated to manage government debt, issue
currency and provide liquidity between bonds and cash Consols quickly became a “byword for financial security” and a benchmark for
other risky assets Alexander Hamilton (1789) created “Hamilton 6s” to refinance existing US debt –
the first US federal bonds based on the Consols Created the first US central bank, modeled on the Bank of England
The British system of public debt was widely adopted worldwide – Holland (1814), Italy (1893), Japan (1880’s)
Post World War 1 – the British Treasury developed more maturities of debt to supplement Consols The first “gilt edged government securities” were introduced
5
The Evolution of Sovereign DebtThe magnitude of government budget deficits and consequently, the outstanding volume of sovereign debt has fluctuated significantly over the years
France, Russia and Italy averaged high deficits in the 18th and 19th century. The UK had the best record for balanced budget
Between the years of 1816 – 1899: UK – Only 4 years with a deficit >1% of GNP. Average budget surplus of 4.6% France – Only 7 years with a budget surplus during this period. Italy – Ran a deficit every year from 1862 – 1899 USA – Average deficit of 1% of GNP
Deficits were vastly larger during the World Wars particularly in combatant nations World War 1 Average Deficit : UK - 30% of GNP, Germany 40%, Italy 22% World War 2: Soviet Union – 19% of GNP, Germany 36%. Axis countries relied heavily on short term borrowings, while the US and UK had
more balanced maturity structures of sovereign debt “Wars of credit” - between 1776 and 1783, bonds financed 40% of the UK’s war
expenditure Short term debt (Bills) gained in popularity, as the attractiveness of long dated
war bonds declined
6
The Evolution of Sovereign Debt Contd...
Early European kingdoms were notoriously prone to defaulting on sovereign debt. Defaults could be declared in many ways – the most common types were: Outright Default – Suspension of principal or interest payments Moratoria/ Rescheduling - Institutionalized processes to make creditors agree
to new terms on the debt Conversions – the exchange of one class of bond for another, usually with a
lower coupon or higher maturity. In the UK, conversions were always negotiated, while in other countries they could be imposed upon creditors.
Some well known examples of sovereign defaults: Spain & France defaulted on all or part of their debt, over 10 times in the 16th
and 17th centuries The UK declared a moratorium on interest payments in the 1680’s and
converted some debt Turkey defaulted in 1875, and after World War I Latin American countries like Brazil, Mexico and Colombia were “perennial
defaulters” in the late 19th and 20th centuries
7
Factors Influencing Sovereign Debt Spreads
The credit spread or ”yield” is the main determinant of the borrowing cost for a country. According to traditional economic theory, spreads are determined by:
Expectations of real growth prospects, nominal interest rates and inflation for the country in question (Fisher Effect, Gibson’s Paradox)
They are thought to be linked to measures of “monetary growth” , “fiscal stability”, and the overall term structure of interest rates
The credit spread is viewed as a premium for default risk and other risks specific to the issuing country
Political and other types of idiosyncratic risks The “Feel good” factor – psychology and economics
Economic policy and its effect on the morale of the public “It’s the economy stupid” – Bill Clinton
The eternal Fiscal Policy question - do higher debts lead to higher interest rates? Regression analysis of UK data from 1727 shows a very low relationship between
yields and the debt/GNP and deficit/GNP Ratio However in the late 1970’s and 1980’s there is evidence of strong positive
correlation between debt/GNP ratios and rising real interest rates.
8
Overview of Methodologies
To develop an explanatory model for sovereign debt spreads we created three methodologies:
1. Using World Bank (WB) annual data after correcting for missing data
2. Using World Bank (WB) annual data but transforming it to monthly by replicating the annual data (independent variables) 12 times but using actual monthly spreads (dependent variable)
3. Using ICRG monthly data
Next we tested for viable trading strategies:1. For each of the explanatory models developed above, we
developed a predictive model using in sample data and tested the model on out of sample data
2. Tested for a momentum trading strategy
9
Overview of Regression Analysis
Stata used for regression analysis Assumed that there would be fixed time effects.
Eliminated these effects by using time dummies for each year
Used cluster standard errors Ensured that independent variable correlations and
multicollinearity were within reasonable levels Generated partial regression plots and checked for
any unusual or influential points Finally, tested that the regression residuals for
normality
10
Model 1: WB Annual
World Bank Annual Data
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WB Annual: Regression Variables
Dependent Variable: Ln(Spread)
Independent Variable: GDP Per Capita, Reserves Per Capita, External Debt as a Percent of GDP
We expect spreads to be: Lower for higher GDP Per Capita Lower for higher Reserves per Capita numbers Higher for higher External Debt as a Percent of GDP
This was consistent with our regression results
12
WB Annual: Modifications to Data
Lack of data for certain years for certain variables presented a problem
In general we excluded the years or countries for which data was missing
In one case we modified the data. Data for the independent variable “External Debt as a percent of GDP” was sometimes missing for certain years or for a specific country altogether. To handle this situation, we made the following modifications: Where the data was missing for a specific year but the country
had data for previous years, we simply used the country data from previous years
Where data was completely missing for the country, we used the average across all countries for the particular year
13
WB Annual: Variables Graph
Scatter plot of spread against independent variables shows that points with Spreads = 1 ( Ln(Spread) =0 ) are outliers
Whether this is a problem will be confirmed if the Partial Regression Plots shows similar influential points
14
WB Annual: Regression Results
Regression gives high (within) R-Square of 85.80% and overall R-Square of 84.45%
The t-stats are all significant
Fixed-effects (within) regression Number of obs = 267 Group variable (i): year Number of groups = 11 R-sq: within = 0.8580 Obs per group: min = 4 between = 0.9513 avg = 24.3 overall = 0.8485 max = 33 F(3,264) = 1494.43 corr(u_i, Xb) = 0.0807 Prob > F = 0.0000 (Std. Err. adjusted for 11 clusters in year) ------------------------------------------------------------------------------ | Robust lnspread | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- gdppercapita | -.0002804 9.58e-06 -29.28 0.000 -.0003017 -.0002591 reservespe~a | -.0007464 .00014 -5.33 0.000 -.0010583 -.0004344 externalde~p | 1.554783 .6288551 2.47 0.033 .1536062 2.955959 _cons | 7.382482 .4902899 15.06 0.000 6.290048 8.474916 -------------+---------------------------------------------------------------- sigma_u | .53247918 sigma_e | 1.0329095 rho | .20995742 (fraction of variance due to u_i) ------------------------------------------------------------------------------
15
WB Annual: Correlation & Multicollinearity
| lnspread gdpper~a reserv~a extern~p -------------+------------------------------------ lnspread | 1.0000 gdppercapita | -0.9009 1.0000 reservespe~a | -0.5422 0.4458 1.0000 externalde~p | 0.3701 -0.3038 -0.0834 1.0000
Variable | VIF 1/VIF -------------+---------------------- gdppercapita | 1.37 0.729692 reservespe~a | 1.25 0.798312 externalde~p | 1.11 0.904308 -------------+---------------------- Mean VIF | 1.24
Variable Correlation:
Low correlation between variables
Multicollinearity:
A VIF (variance inflation factor) lower than 10 denotes low collinearity
16
WB Annual: Partial Regression Plots
Partial Regression Plot does not reveal any unusual or influential observations.
17
WB Annual: Residual Plots
Test for Normality: There is a slight skew but overall residuals are normally distributed
18
WB Annual: Trading Strategy Methodology
In Sample Period: 1994 – 2001 Out of Sample Period: 2002 – 2003 Predictive Equation:
Ln(Spread) (1-year forward) = 8.64547 – 0.00031 * GDP Per Capita – 0.00108 * Reserves Per Capita
Sorted on the % Change expected during the next year % Change = (Next year forecasted spread - Current Spread) / Current Spread
If % Expected Change is negative, the decision is to buy the country’s debt Conversely if % Expected Change is positive, the decision is to sell the country’s debt Eliminated developed countries which had spreads = 1
Long Short Strategy: After sorting, selected the top quintile (five most negative % Expected Change) to go long and bottom five quintile (most positive % Expected Change) to go short
Long Only Strategy: After sorting, selected the top two quintiles (ten most negative % Expected Change) to go long only
19
WB Annual: Trading Strategy Results
Overall Accuracy: The overall accuracy was 73% and 56% in the two years.
Long Short Result: The % Accuracy during the two years of OOS data is over 50% in both the OOS years.
Long Only Result: The % Accuracy is 100% and 90% in the two years. These results are very promising.
Year Long Short Long Only Overall2002 50% 100% 73%2003 60% 90% 56%
Directional Accuracy
Trading Strategies Comparison
0%
20%
40%
60%
80%
100%
2002 2003
Year
% A
ccu
racy Long Short
Long Only
Overall
20
WB Annual: Conclusions
Strong explanatory power of World Bank annual data. Gives us R-Sq in the 85% range
Long only Trading Strategy shows a lot of promise Need to explore reasons why the short side of the
strategy does not yield as good results
21
Model 2: WB Monthly
World Bank Annual Data
converted to Monthly
22
WB Monthly: Regression Variables
Dependent Variable: Ln(Spread)
Independent Variable: GDP Per Capita, Reserves Per Capita, External Debt as a Percent of GDP
We expect spreads to be: Lower for higher GDP Per Capita Lower for higher Reserves per Capita numbers Higher for higher External Debt as a Percent of GDP
This was consistent with our regression results
23
WB Monthly: Modifications to Data
Starting with the WB annual data used in Model 1, we made the following modifications:
1. We replicated the annual data (independent variables) 12 times, once for each month of the year
2. used the actual monthly spreads (dependent variable)
3. Ran our regressions and our trading strategy as if we had monthly data
24
WB Monthly: Variables Graph
Scatter plot of spread against independent variables shows that points with Spreads = 1 ( Ln(Spread) =0 ) are outliers
Whether this is a problem will be confirmed if the Partial Regression Plots shows similar influential points
25
WB Monthly: Regression Results
Regression gives high (within) R-Square of 85.22% and overall R-Square of 84.48%
The t-stats are all very significant
Fixed-effects (within) regression Number of obs = 2957 Group variable (i): year Number of groups = 11 R-sq: within = 0.8522 Obs per group: min = 33 between = 0.9577 avg = 268.8 overall = 0.8448 max = 369 F(3,2954) = 2931.56 corr(u_i, Xb) = 0.0714 Prob > F = 0.0000 (Std. Err. adjusted for 11 clusters in year) ------------------------------------------------------------------------------ | Robust lnspread | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- gdppercapita | -.0002817 9.45e-06 -29.80 0.000 -.0003028 -.0002607 reservespe~a | -.0006339 .0001369 -4.63 0.001 -.0009388 -.0003289 externalde~p | 1.482868 .6366234 2.33 0.042 .0643827 2.901353 _cons | 7.333897 .4741553 15.47 0.000 6.277413 8.390381 -------------+---------------------------------------------------------------- sigma_u | .56187781 sigma_e | 1.0392333 rho | .22619749 (fraction of variance due to u_i) ------------------------------------------------------------------------------
26
WB Monthly: Correlation & Multicollinearity
Variable Correlation:
Low correlation between variables, the highest being 50.27%
Multicollinearity:
A VIF (variance inflation factor) lower than 10 denotes low collinearity
| lnspread gdpper~a reserv~a extern~p -------------+------------------------------------ lnspread | 1.0000 gdppercapita | -0.9044 1.0000 reservespe~a | -0.5648 0.5027 1.0000 externalde~p | 0.4019 -0.3509 -0.0904 1.0000
Variable | VIF 1/VIF -------------+---------------------- gdppercapita | 1.53 0.653220 reservespe~a | 1.35 0.738856 externalde~p | 1.15 0.866977 -------------+---------------------- Mean VIF | 1.35
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WB Monthly: Partial Regression Plots
Partial Regression Plot does not reveal any unusual or influential observations. The horizontal bars are because we have replicated the annual independent variable data 12 times.
28
WB Monthly: Residual Plots
Test for Normality: There is a slight skew but overall residuals are normally distributed
29
WB Monthly: Trading Strategy Methodology- 1Methodology – 1 uses 1-month predictive model
In Sample Period: 1994 Jan – 2002 Dec Out of Sample Period: 2003 Jan – 2004 Nov Predictive Equation:
Ln(Spread) (1-month forward) = 8.090379 – 0.00029 * GDP Per Capita – 0.001111 * Reserves Per Capita
+ 0.580377 * External Debt as a % of GDP
Sorted on the % Change expected during the next month % Change = (Next month forecasted spread - Current Spread) / Current Spread
If % Expected Change is negative, the decision is to buy the country’s debt Conversely if % Expected Change is positive, the decision is to sell the country’s debt Long Short Strategy: After sorting, selected the top quintile (five most negative %
Expected Change) to go long and bottom five quintile (most positive % Expected Change) to go short
Long Only Strategy: After sorting, selected the top two quintiles (ten most negative % Expected Change) to go long only
30
WB Monthly: Trading Strategy Results - 1
Trading Strategies Comparison
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Jan-
03
Mar
-03
May
-03
Jul-0
3
Sep-0
3
Nov-03
Jan-
04
Mar
-04
May
-04
Jul-0
4
Sep-0
4
Nov-04
Month
% A
ccu
racy Long short
Long Only
Overall
Month Long short Long Only OverallJan-03 30% 40% 43%Feb-03 70% 70% 65%Mar-03 50% 80% 57%Apr-03 60% 70% 64%
May-03 50% 40% 45%Jun-03 60% 80% 65%Jul-03 20% 60% 39%
Aug-03 60% 70% 65%Sep-03 60% 60% 52%Oct-03 50% 60% 57%Nov-03 40% 60% 52%Dec-03 60% 30% 43%Jan-04 60% 40% 61%Feb-04 40% 70% 52%Mar-04 50% 40% 48%Apr-04 50% 10% 35%
May-04 40% 50% 52%Jun-04 60% 90% 65%Jul-04 50% 70% 61%
Aug-04 50% 70% 39%Sep-04 70% 70% 52%Oct-04 50% 90% 61%Nov-04 70% 70% 57%
Average 52% 60% 54%
Overall Accuracy: The overall accuracy ranged from 39% to 66%, and the average was 54%
Long Short Result: The % Accuracy ranged from 20% to 70%, and the average was 52%. In its current form, this strategy doesn’t show much promise
Long Only Result: The % Accuracy ranged from 30% to 90% and the average was 60%. In 17 of the 23 projected months, the % Accuracy was 50% or higher. This is a potentially viable trading strategy
31
WB Monthly: Trading Strategy Methodology- 2Methodology – 2 uses 1-year predictive model
In Sample Period: 1994 Jan – 2001 Dec Out of Sample Period: 2002 Jan – 2003 Dec Predictive Equation:
Ln(Spread) (1-year forward) = 8.491300 – 0.000295 * GDP Per Capita – 0.001160 * Reserves Per Capita
Sorted on the % Change expected during the next year % Change = (Next year forecasted spread - Current Spread) / Current Spread
If % Expected Change is negative, the decision is to buy the country’s debt Conversely if % Expected Change is positive, the decision is to sell the country’s debt Long Short Strategy: After sorting, selected the top quintile (five most negative %
Expected Change) to go long and bottom five quintile (most positive % Expected Change) to go short
Long Only Strategy: After sorting, selected the top two quintiles (ten most negative % Expected Change) to go long only
32
WB Monthly: Trading Strategy Results - 2
Overall Accuracy: The overall accuracy ranged from 50% to 82%, and the average was 65%. It was over 50% for all the months
Long Short Result: The % Accuracy ranged from 40% to 80%, and the average was 60%. In 23 of the 24 projected months, the % Accuracy was 50% or higher. This strategy can be explored further
Long Only Result: The % Accuracy ranged from 30% to 100% and the average was 86%. In 23 of the 24 projected months, the % Accuracy was 50% or higher. In 17 of the 24 months, the % Accuracy was 90% - 100%. This strategy represents a viable trading strategy and needs to be explored further
Trading Strategies Comparison
0%
20%
40%
60%
80%
100%
120%
Jan-
03
Mar
-03
May
-03
Jul-0
3
Sep-0
3
Nov-03
Jan-
04
Mar
-04
May
-04
Jul-0
4
Sep-0
4
Nov-04
Month
% A
ccu
racy Long short
Long Only
Overall
Month Long short Long Only Overall
Jan-02 70% 50% 55%Feb-02 60% 50% 55%Mar-02 70% 30% 59%Apr-02 50% 60% 64%
May-02 80% 90% 71%Jun-02 70% 100% 77%Jul-02 70% 100% 82%
Aug-02 60% 100% 77%Sep-02 60% 100% 82%Oct-02 50% 100% 68%Nov-02 50% 100% 64%Dec-02 50% 100% 64%Jan-03 50% 100% 68%Feb-03 50% 100% 64%Mar-03 50% 90% 59%Apr-03 60% 100% 64%
May-03 70% 80% 67%Jun-03 40% 70% 55%Jul-03 60% 90% 55%
Aug-03 60% 90% 64%Sep-03 60% 90% 59%Oct-03 70% 100% 77%Nov-03 70% 90% 59%Dec-03 60% 90% 50%
Average 60% 86% 65%
33
WB Monthly: Conclusions
Strong explanatory power of World Bank monthly data. Gives us R-Sq in the 85% range
Trading strategy using 1-Year lag holds the most promise Long Short Trading Strategy shows some promise Long only Trading Strategy represents a viable trading
strategy and needs to be explored further Need to explore reasons why the short side of the strategy
does not yield good results
34
Model 3: ICRG Monthly
ICRG Monthly Data
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ICRG Country Ratings Overview The International Country Risk Guide (ICRG) methodology
Developed in 1980, by the editors of the newsletter International Reports Considers 22 total variables under 3 categories of risks – Economic,
Financial and Political with separate indices for each category Economic (50 Points)
GDP/ Head, Real GDP growth, Inflation, Fiscal & Current Account Deficit
Financial (50 Points) % of Foreign Debt, Exchange Rate stability, Debt Service, Current
Account % of Exports Political (100 Points – Scale from 1-12)
Government Stability, Socioeconomic Conditions, Corruption, Law & Order
These 3 indices are used to produce a composite score out of 100 80 – 100: Very Low Risk Countries 0 – 49.5: Very High Risk Countries
The ICRG team generates current, 1 year and 5 year forecasts for each risk category as well as for the 3 separate indices
36
ICRG Monthly: Regression Variables
Dependent Variable: Ln(Spread)
Independent Variable: GDP Per Head Annual Inflation Rate Foreign Debt as a Percent of GDP
We expect spreads to be: Lower for higher GDP Per Head Higher for higher Annual Inflation rates Higher for higher Foreign Debt as a Percent of GDP
This was consistent with our regression results
37
ICRG Monthly: Variables Graph
Scatter plot of spread against independent variables shows that points with Spreads = 1 ( Ln(Spread) =0 ) are outliers
Whether this is a problem will be confirmed if the Partial Regression Plots shows similar influential points
38
ICRG Monthly: Regression Results
Regression gives a (within) R-Square of 64.67% and overall R-Square of 63.26%
The t-stats are all very significant
Fixed-effects (within) regression Number of obs = 3910 Group variable (i): year Number of groups = 13 R-sq: within = 0.6467 Obs per group: min = 4 between = 0.1186 avg = 300.8 overall = 0.6326 max = 436 F(3,3907) = 748.37 corr(u_i, Xb) = -0.0196 Prob > F = 0.0000 (Std. Err. adjusted for 13 clusters in year) ------------------------------------------------------------------------------ | Robust lnspread | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- gdpheade | -.9568297 .0356213 -26.86 0.000 -1.034442 -.8792177 inflatione | -.3191931 .0336124 -9.50 0.000 -.3924281 -.245958 fordebtf | -.3175541 .0171611 -18.50 0.000 -.3549449 -.2801632 _cons | 11.32238 .2604515 43.47 0.000 10.75491 11.88986 -------------+---------------------------------------------------------------- sigma_u | .61515417 sigma_e | 1.4789064 rho | .14749679 (fraction of variance due to u_i) ------------------------------------------------------------------------------
39
ICRG Monthly: Correlation & Multicollinearity
Variable Correlation:
Low correlation between variables
Multicollinearity:
A VIF (variance inflation factor) lower than 10 denotes low collinearity
| lnspread gdpheade inflat~e fordebtf -------------+------------------------------------ lnspread | 1.0000 gdpheade | -0.6985 1.0000 inflatione | -0.4944 0.2705 1.0000 fordebtf | -0.5241 0.3898 0.2962 1.0000
Variable | VIF 1/VIF -------------+---------------------- fordebtf | 1.24 0.808789 gdpheade | 1.22 0.821705 inflatione | 1.13 0.883881 -------------+---------------------- Mean VIF | 1.19
40
ICRG Monthly: Partial Regression Plots
Partial Regression Plot does not reveal any unusual or influential observations.
41
ICRG Monthly: Residual Plots
Test for Normality: The curve is doesn’t follow the normal curve too closely especially in the first half. But broadly the residuals are normally distributed.
42
ICRG Monthly: Trading Strategy Methodology- 1Methodology – 1 uses 1-month predictive model
In Sample Period: 1993 Dec – 2003 Dec Out of Sample Period: 2004 Jan – 2005 Nov Predictive Equation:
Ln(Spread) (1-month forward) = 11.05438 – 0.94991 * GDP Per Head Rating – 0.33263 * Annual Inflation Rate Rating
- 0.30559 * Foreign Debt as a % of GDP Rating
Sorted on the % Change expected during the next month % Change = (Next month forecasted spread - Current Spread) / Current Spread
If % Expected Change is negative, the decision is to buy the country’s debt Conversely if % Expected Change is positive, the decision is to sell the country’s debt Long Short Strategy: After sorting, selected the top quintile (five most negative %
Expected Change) to go long and bottom five quintile (most positive % Expected Change) to go short
Long Only Strategy: After sorting, selected the top two quintiles (ten most negative % Expected Change) to go long only
43
ICRG Monthly: Trading Strategy Results - 1
Overall Accuracy: The overall accuracy ranged from 32% to 75%, and the average was 55%
Long Short Result: The % Accuracy ranged from 20% to 70%, and the average was 50%. In 14 of the 23 projected months, the % Accuracy was above 50%. We cannot use this strategy in its current form
Long Only Result: The % Accuracy ranged from 0% to 100% and the average was 60%. In 16 of the 23 projected months, the % Accuracy was 50% or higher. This is a potentially viable trading strategy but would have to be refined further
Trading Strategies Comparison
0%
20%
40%
60%
80%
100%
120%
Jan-
04
Mar
-04
May
-04
Jul-0
4
Sep-0
4
Nov-04
Jan-
05
Mar
-05
May
-05
Jul-0
5
Sep-0
5
Nov-05
Month
% A
ccu
racy Long Short
Long Only
Overall
Month Long Short Long Only OverallJan-04 70% 40% 61%Feb-04 70% 100% 64%Mar-04 40% 30% 32%Apr-04 40% 10% 36%
May-04 30% 60% 50%Jun-04 60% 90% 64%Jul-04 50% 80% 75%
Aug-04 20% 70% 54%Sep-04 50% 70% 71%Oct-04 50% 100% 64%Nov-04 70% 70% 68%Dec-04 30% 60% 50%Jan-05 60% 90% 43%Feb-05 50% 0% 54%Mar-05 60% 30% 48%Apr-05 40% 60% 56%
May-05 40% 80% 59%Jun-05 50% 80% 59%Jul-05 50% 50% 61%
Aug-05 60% 100% 57%Sep-05 40% 20% 36%Oct-05 40% 50% 50%Nov-05 70% 30% 50%
Average 50% 60% 55%
44
ICRG Monthly: Trading Strategy Methodology- 2Methodology – 2 uses 1-year predictive model
In Sample Period: 1993 Dec – 2002 Dec Out of Sample Period: 2003 Jan – 2004 Dec Predictive Equation:
Ln(Spread) (1-year forward) = 11.10612 – 0.97069 * GDP Per Head Rating – 0.28848 * Annual Inflation Rate Rating
- 0.31489 * Foreign Debt as a % of GDP Rating
Sorted on the % Change expected during the next year % Change = (Next year forecasted spread - Current Spread) / Current Spread
If % Expected Change is negative, the decision is to buy the country’s debt Conversely if % Expected Change is positive, the decision is to sell the country’s debt Long Short Strategy: After sorting, selected the top quintile (five most negative %
Expected Change) to go long and bottom five quintile (most positive % Expected Change) to go short
Long Only Strategy: After sorting, selected the top two quintiles (ten most negative % Expected Change) to go long only
45
ICRG Monthly: Trading Strategy Results - 2
Overall Accuracy: The overall accuracy ranged from 43% to 67%, and the average was 56%.
Long Short Result: The % Accuracy ranged from 40% to 80%, and the average was 55%. In 19 of the 24 projected months, the % Accuracy was 50% or higher. This strategy can be explored further
Long Only Result: The % Accuracy ranged from 70% to 100% and the average was 89%. This result represents a viable trading strategy and needs to be explored further
Trading Strategies Comparison
0%
20%
40%
60%
80%
100%
120%
Jan-
03
Mar
-03
May
-03
Jul-0
3
Sep-0
3
Nov-03
Jan-
04
Mar
-04
May
-04
Jul-0
4
Sep-0
4
Nov-04
Month
% A
ccu
racy Long Short
Long Only
Overall
Month Long Short Long Only Overall
Jan-03 50% 90% 57%Feb-03 50% 90% 54%Mar-03 60% 90% 61%Apr-03 40% 90% 61%
May-03 50% 80% 52%Jun-03 40% 70% 50%Jul-03 50% 90% 64%
Aug-03 70% 70% 57%Sep-03 50% 70% 57%Oct-03 60% 90% 54%Nov-03 80% 100% 64%Dec-03 60% 100% 57%Jan-04 70% 90% 54%Feb-04 70% 100% 54%Mar-04 40% 80% 50%Apr-04 80% 90% 67%
May-04 40% 90% 52%Jun-04 50% 100% 59%Jul-04 60% 100% 64%
Aug-04 50% 90% 57%Sep-04 60% 100% 54%Oct-04 40% 90% 43%Nov-04 50% 80% 43%
Average 55% 89% 56%
46
ICRG Monthly: Conclusions
Explanatory power of ICRG data was surprising below that of the World Bank monthly data. This gave us R-Sq in the 63% range compared to 85% range for WB data
Trading strategy using 1-Year lag holds the most promise Long Short Trading Strategy shows some promise with 19
of the 24 months having over 50% accuracy Long only Trading Strategy represents a viable trading
strategy but needs to be explored further Need to explore reasons why the short side of the strategy
does not yield good results
47
Model 4: Lagged Spreads
Monthly Spreads Regressed on 1-Month Lagged Spreads
48
Lagged Spreads: Regression Variables
Dependent Variable: Ln(Spread)
Independent Variable: Ln(Spread) 1-Month Lag Foreign Debt Service as a Percent of Exports of Goods and
Services We expect spreads to be:
Higher if the previous month spread was high due to a momentum effect.
Higher for higher Foreign Debt Service ratio. A high ratio shows that a country may default in the near future.
This was consistent with our regression results
49
Lagged Spreads: Variables Graph
The Graph above shows extremely high correlation of the lagged spreads with the current spreads
50
Lagged Spreads: Regression Results
Regression gives extremely high (within) R-Square of 96.93% and overall R-Square of 96.96%
The t-stats are all significant
Fixed-effects (within) regression Number of obs = 3869 Group variable (i): year Number of groups = 12 R-sq: within = 0.9693 Obs per group: min = 67 between = 0.9903 avg = 322.4 overall = 0.9696 max = 435 F(2,3867) = 38349.32 corr(u_i, Xb) = -0.0290 Prob > F = 0.0000 (Std. Err. adjusted for 12 clusters in year) ------------------------------------------------------------------------------ | Robust lnspread | Coef. Std. Err. t P>|t| [95% Conf. Interval] -------------+---------------------------------------------------------------- lnspread1m~g | .9672258 .0134447 71.94 0.000 .9376343 .9968173 debtservf | -.0429803 .0203903 -2.11 0.059 -.087859 .0018984 _cons | .5121753 .2146835 2.39 0.036 .03966 .9846905 -------------+---------------------------------------------------------------- sigma_u | .07105769 sigma_e | .43487784 rho | .02600427 (fraction of variance due to u_i) ------------------------------------------------------------------------------
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Lagged Spreads: Correlation & Multicollinearity
Variable Correlation:
Low correlation between variables
Multicollinearity:
A VIF (variance inflation factor) lower than 10 denotes low collinearity
| lnspread lnspre~g debtse~f -------------+--------------------------- lnspread | 1.0000 lnspread1m~g | 0.9841 1.0000 debtservf | -0.0967 -0.0646 1.0000
Variable | VIF 1/VIF -------------+---------------------- debtservf | 1.00 0.995828 lnspread1m~g | 1.00 0.995828 -------------+---------------------- Mean VIF | 1.00
52
Lagged Spreads: Partial Regression Plots
Partial Regression Plot shows the extremely high correlation between lagged and current spreads.
53
Lagged Spreads: Residual Plots
Test for Normality: The curve is doesn’t follow the normal curve throughout the curve and this shows a potential problem with this model
54
Lagged Spreads: Trading Strategy Methodology
In Sample Period: 1993 Dec – 2003 Dec Out of Sample Period: 2004 Jan – 2005 Nov Predictive Equation:
Ln(Spread) (1-month forward) = -0.40302 + 1.00144 * Ln(Spread) + 0.04623 * Debt Service Ratio Rating
(The positive sign for the Debt Service Ratio coefficient on the in sample regression came as a surprise especially because the sign was negative in the explanatory model. This despite the low variable correlation and high t-stats. We reasoned that if a country has a high Debt Service ratio today, it might be making efforts to reduce its debt which would lead to fall in future spreads)
Sorted on the % Change expected during the next month % Change = (Next month forecasted spread - Current Spread) / Current Spread
If % Expected Change is negative, the decision is to buy the country’s debt Conversely if % Expected Change is positive, the decision is to sell the country’s debt Long Short Strategy: After sorting, selected the top quintile (five most negative %
Expected Change) to go long and bottom five quintile (most positive % Expected Change) to go short
Long Only Strategy: After sorting, selected the top two quintiles (ten most negative % Expected Change) to go long only
55
Lagged Spreads: Trading Strategy Results
Overall Accuracy: The overall accuracy ranged from 32% to 75%, and the average was 50%
Long Short Result: The % Accuracy ranged from 0% to 80%, and the average was 50%. In 14 of the 23 projected months, the % Accuracy was 50% or higher. We cannot use this strategy in its current form
Long Only Result: The % Accuracy ranged from 0% to 100% and the average was 57%. In 14 of the 23 projected months, the % Accuracy was 50% or higher. Again we cannot use this strategy in its current form
Trading Strategies Comparison
0%
20%
40%
60%
80%
100%
120%
Jan-
04
Mar
-04
May
-04
Jul-0
4
Sep-0
4
Nov-0
4
Jan-
05
Mar
-05
May
-05
Jul-0
5
Sep-0
5
Nov-0
5
Month
% A
cc
ura
cy
Long Short
Long Only
Overall
Month Long Short Long Only OverallJan-04 70% 40% 39%Feb-04 60% 90% 54%Mar-04 40% 10% 32%Apr-04 40% 10% 43%
May-04 60% 70% 61%Jun-04 60% 100% 75%Jul-04 40% 60% 54%
Aug-04 40% 60% 46%Sep-04 40% 60% 39%Oct-04 50% 100% 57%Nov-04 70% 80% 68%Dec-04 0% 30% 32%Jan-05 70% 100% 61%Feb-05 50% 0% 46%Mar-05 40% 10% 41%Apr-05 50% 80% 48%
May-05 40% 80% 48%Jun-05 60% 100% 59%Jul-05 50% 40% 43%
Aug-05 50% 90% 50%Sep-05 10% 0% 32%Oct-05 80% 60% 50%Nov-05 80% 40% 64%
Average 50% 57% 50%
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Lagged Spreads: Conclusions
Explanatory power of ICRG data was surprisingly high with R-Sq over 96% much higher than all other models
However the residuals did not show a normal distribution – there might be potential problems with the model
Trading strategy using 1-month lag did not show much promise. The results lacked any consistency
57
Momentum Strategy Given the high correlation of lagged monthly spread with current
spread, we felt that a momentum strategy should work well We calculated the monthly change in spread (CAGR) for last 6
months, 3 months and 1 month If the current month CAGRs are higher than previous month
CAGRs in at least two of the above three calculations, then the decision is to sell, else buy
Result: The percent accuracy of this strategy (after ignoring all the records with spreads = 1) was 49%. This was well below what we would have liked in a good trading strategy
Conclusion: There is promise in this strategy but it needs to be explored further
58
Issues to be Explored Further
Despite attempting several trading strategies it was difficult to come up with a convincing one
The short side of the Long-short strategy was especially poor and would need to be explore
Our OOS was typically for periods in 2003 and 2004 when the economy was coming out of a recession. The results may be skewed because of this effect. We should test the strategy in more “normal” periods
Finally, the momentum strategy seems to hold promise and needs be explored
59
Bibliography
Ferguson, Niall. “The Cash Nexus – Money and Power in the Modern World 1700-2000. Penguin Books. Chapters 4 – 8
Ferguson, Niall. “Paper & Iron – Hamburg business and German politics in the era of inflation, 1897 – 1927”
The International Country Risk Guide, http://www.icrgonline.com/page.aspx?page=icrgmethods#Background_of_the_ICRG_Rating_System
The University of California, Los Angeles. “Resources to help you learn and use Stata”
http://www.ats.ucla.edu/stat/stata/ The World Bank, International Monetary Fund and World Markets Research
Center websites.