ENSO and Mexican Children: Medium-Term Effects of Early-Life Weather Shocks on Cognitive and Health Outcomes

1. ENSO and Mexican children
Medium-term effects of early-life weather shocks
on cognitive and health outcomes
Arturo Aguilar Marta Vicarelli
Harvard University
Yale University
November 29, 2012
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2. Motivation
Conditions affecting individuals at early stages of life tend to have long-term
effects
Health, education, socioeconomic status (Maccini and Yang, 2009)
Physical and mental disabilities (Almond, 2006; Almond and
Mazumder, 2011)
Weather shocks are the most important self-reported risk faced by rural
households (Skoufias, 1997; Dercon and Krishnan, 2000; Gine, Townsend
and Vickery, 2008)
El Ni˜o Southern Oscillation (ENSO)
n
Recurring climatic event with a 5 to 7 year cycle
Affects hydro-meteorological patterns causing extreme weather events
(e.g. droughts, floods, heat waves)
Global impacts (Cane et al., 2004)
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3. Research Questions
1 Estimate the effects of ENSO-related weather shocks in early-life on
medium-term individual well-being (human capital formation):
Cognitive development
Health and physical development
Motor skills
2 Investigate possible mechanisms through which weather shocks could be
driving these results
Income
Nutrition
Health
3 Assess the potential mitigating effects of a randomized poverty reduction
intervention: Mexico’s Progresa Conditional Cash Transfer program
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4. Contributions and related literature
1 Long-term effects of shocks in early-childhood
Maccini and Yang (2009), Almond (2006), Almond and Mazumder
(2011)
Contribution: Examines specific medium-term effects on human-capital
formation (e.g. memory, language development) which might be
driving long-term effects
2 Role of weather shocks
Maccini and Yang (2009), Munshi (2003), Baez and Santos (2007)
Contribution: Use ENSO-related extreme rain shocks at the end of the
agricultural season to identify exogenous income shocks
3 Progresa’s effects
Fernald et al. (2008), Fernald and Gertler (2005), Gertler (2004)
Contribution: Determine if the Conditional Cash Transfers provided
mitigation effects to children affected by the shocks
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5. A glimpse at the results
Main Results
Four to five years after the shock, exposed children show:
Lower cognitive abilities (11 to 21 percent)
Receptive language, working memory, and visual-spatial processing
Lower weight (0.28 to 0.38 kg) and lower height (1.1 to 1.8 cm)
Minor reduction in gross motor skills
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6. A glimpse at the results
Mechanisms
The ENSO-related weather shock had contemporaneous and persistent effects
Income: contraction up to 2 years after the shock
Food consumption and diet composition: negatively affected
Health: no significant self-reported effect immediately after the shock
Role of Progresa
No evidence of Progresa’s mitigating effects has been found
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7. Outline
1 Background
2 Data
3 Empirical specification
4 Results
5 Mechanisms
6 The role of Progresa
7 Conclusions
Aguilar & Vicarelli (Harvard, Yale) ENSO and Mexican children November 29, 2012 7 / 63

8. El Ni˜o Southern Oscillation
n
ENSO is a non-regular cyclical climatic pattern associated to changes in
tropical Pacific Ocean sea surface temperature and pressure.
ENSO generates weather extremes across the globe, especially in countries
bordering the Pacific Ocean.
El Ni˜o 1997-1998
n
La Ni˜a 1998-1999
n
Sizeable effects in weather-sensitive industries (e.g. fishing and agriculture)
(Cane et al., 2004)
Large effects for developing countries that rely on rain-fed agriculture (90%
of households in our sample)
Use extreme floods during the harvest season as exogenous income shocks
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9. El Ni˜o Southern Oscillation
n
Figure: Satellite image showing sea surface heights relative to normal conditions. Red and
white areas are related to above average sea surface temperatures and blue and purple areas to
below average sea surface temperatures
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10. Outline
1 Background
2 Data
3 Empirical specification
4 Results
5 Mechanisms
6 The role of Progresa
7 Conclusions
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11. Data: Weather
Gridded precipitation data
Source: UEA CRU TS2p1 (Mitchell, 2005)
Temporal resolution: monthly
Spatial resolution: 0.5 x 0.5 degrees
We calculate the Monthly Standardized Anomaly
Anomaly = difference with respect to 1960-1999 average levels
Standardized = measured in standard deviation terms
Weather shock definition:
rain shock = 1 if standardized anomaly for Sep-Oct > 0.7
Sensitivity tests using different thresholds
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12. Data: Weather
Standardized anomaly is above 0.7 about 16% of the time
Standardized anomaly distribution (Sept-Oct)
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13. Data: Weather
Monthly Precipitation Standardized Anomalies
4 Growing Season
A M J JJ A S O N
2
0
-2
97 98 99 Year
Figure: Maize calendar: Planting season (Apr-Jun). Moisture sensitive season
(Jul-Aug). Maturation and Harvesting (Sep-Nov)
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14. Data: Weather
Precipitation Standardized Anomalies (UEA CRU Ts2p1) 1999
30˚N
25˚N
Latitude
20˚N
15˚N
120˚W 115˚W 110˚W 105˚W 100˚W 95˚W 90˚W
Longitude
Oct 1999
-2.4 -2 -1.6 -1.2 -0.8 -0.4 0 0.4 0.8 1.2 1.6 2 2.4
precipitation
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15. Data: Weather
We spatially joined
Weather and Socioeconomic Data
24°0'0"N
30˚N
22°0'0"N
25˚N
Latitude
20°0'0"N
20˚N
15˚N
18°0'0"N
120˚W 115˚W 110˚W 105˚W 100˚W 95˚W 90˚W
Longitude
Oct 1999 104°0'0"W 102°0'0"W 100°0'0"W 98°0'0"W 96°0'0"W
-2.4 -2 -1.6 -1.2 -0.8 -0.4 0 0.4 0.8 1.2 1.6 2 2.4
precipitation
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