time matters: ‘short’ term vs. ‘medium’ term impacts

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Name Date Event Location

Time matters: ‘short’ term vs. ‘medium’ term impacts

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Soumya Balasubramanya Making Impact Evaluation Matter: Better Evidence for Effective Policies and Programs

September 3-5, 2014 Manila, Philippines

Balasubramanya, S., Pfaff, A., Bennear, L., Tarozzi, A., Ahmed, K.M., van Geen, A. (2014). Evolution of households’ responses to the groundwater arsenic crisis in Bangladesh: information on environmental health risks can have increasing behavioral impact over time. Environment and Development Economics, 19(05), pp. 631-647.


Summary • Impact of an arsenic information and testing campaign on

adoption of risk-avertive behaviors over time. • Followed households over two time periods and tracked

behaviors and perceptions over 2003-05 and 2005-08. • Impact of information on risk-avertive behaviors depends

on ability to recall information – Households that recalled: behaviors were persistent and double

the # of households took up behaviors over time – Households that didn't’ recall: observed perverse behaviors

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Background

• GW is primary drinking source; accessed through private tubewells (shallow, < 30 m; 90% of wells are shallow )

• GW contaminated with naturally occurring arsenic; unpredictable in shallow aquifer

• WB- funded countrywide groundwater testing program

b/w 1999-2003 • Tested households’ tubewells for arsenic; painted spouts

red/green • Encouraged households to share green wells • Village level awareness campaigns • Media campaigns

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What happens within two years of testing?

• Schoenfeld, 2005 – Census of all tubewells tested by WB in 2003; in 62

villages of Araihazar Upazila – Interviewed the wives of the well owners – Recorded color of well (observed by enumerator) – Elicited safety perception (asked respondent if well was

safe or unsafe) – Elicited switching behavior b/w 2003-05

• Switching behaviors from unsafe wells ~20%

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What happens over time?

• Household values both convenience (well nearby) and safe drinking water (green well) – Switch if cost (switching) < benefit (switching)

• Can the costs and benefits change over time? – ‘Social learning’ by observing peers (Miguel and

Kremer, 2004; Munshi and Myaux, 2006) – Household ‘loses’ information – Concern about health risk reduces (Karlan et al., 2010) – Safe well owners reduce access (Fehr and Fischbacher,

2003; Hanchett et al., 2002)

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Two Questions

• Is well-switching a persistent behavior

change?

• How does adoption of well-switching evolve over time?

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Methods and Data

• Follow-up study on households whose switching behaviors had been previously studied in Schoenfeld, 2005 – Randomly selected subset of households in 59 villages – Interviewed same person as in previous survey – 1557 households/wells (1038 unsafe; 519 safe) – Use sampling weights

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Data

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Consistency in recall

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• 78% recalled switching behavior of 2003-2005 consistently • Always consider households with consistent recall

of 2003-2005 switching behavior

• By 2008, no color left on any well spout • 78% recalled well safety consistently (well color = safety perception in 2005 = safety perception in 2008)


Did impact of testing increase or erode over time?

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• Consider households with consistent recall of well tests • If switched in 2003-2005, check if switches were

persistent – 16% of households at unsafe wells switched during 2003-2005

• 14% stayed put • 2% switched to a second well they thought safe

• If did not switch during 2003-2005, check if switched

during 2005-2008 – 17% of households at unsafe-tested wells had switched – Switching over five years doubles that over two years


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What about those that ‘forget’ information?

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• Consider households with inconsistent recall of well tests (remembered correctly in 2005, but not in 2008)

• In 2005

– Paint visible on all wells (1039 red/ 519 green) – Almost all households recalled well safety correctly (97%

unsafe/ 95% safe)

• In 2008 – Paint washed off – 77% unsafe tested households recalled safety accurately – 81% safe tested households recalled safety accurately


Would it help to reinforce provision of arsenic information?

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• Safe-tested hhs that changed safety perceptions after

2005: 26% switched in 2005-2008

• Unsafe-tested hhs that changed safety perceptions after 2005: 11% switched in 2005-2008


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Discussion • Behavioral:

• Recall of arsenic information changes over time • Recall is critical for behavior

• Evaluation: • Short-term evaluations present a snap shot • Impacts are heterogeneous

• Policy perspective:

• Cheap, responsible for most reduction in arsenic exposure (World Bank, 2005; Johnston et al., 2010; Ahmed et al., 2006)

• Supporting continued well testing: new well constantly installed; 1/3 wells untested

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Thank you!

[email protected]

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time matters: ‘short’ term vs. ‘medium’ term impacts

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