By Marc Rockmore
Households in developing countries are particularly vulnerable to shocks. Not only are they disproportionately engaged in shock-prone livelihoods, such as agriculture, but they have often limited financial resources to address any shortfalls. Since these households frequently have little or no access to formal finance, they rely on informal community networks in times of trouble. These networks, however, are often limited in their scope and are easily overwhelmed when confronted with widespread shocks (e.g. covariate shocks), such as natural disasters.
The effects of shocks are therefore widely studied in economics. One particular branch finds that early life exposure to shocks (during the pre-natal period and initial years) can lead to permanent physical and cognitive shortcomings. An emerging literature expands this to consider the impact of early life exposure to weather on adult mental health; while rarely studied in (development) economics, the effects of mental health disorders are both large in magnitude and relatively common in developing countries despite being rarely diagnosed or treated.
In “Early Life Exposure to Above Average Rainfall and Adult Mental Health”, we contribute to this emerging literature by examining the effects of above-average levels of rainfall in early life on adult mental health in Indonesia. This contrasts with a larger literature (both in economics and elsewhere) on early life exposure to heat. Although temperature can have considerable variation, such as Africa (Adhvaryu et al. 2017), this is not true in much of South and South-East Asia. Rather, climate variability arises from shifting rainfall patterns due to phenomena as the El Niño-Southern Oscillation and monsoon rains. While other studies have examined the effects of exposure to rainfall on adult mental health, these have not isolated the effect of above average rainfall.
By combining a national survey and a historical station-level panel of daily rainfall and temperature data, we create individual-specific measures of exposure to rainfall shocks during different early life growth periods: pre-natal, from ages 0 to 1 year, and from 1 to 2 years. We identify the effects of rainfall variation based on the within period variation across communities within the same district. That is, we compare (the rainfall exposure and mental health outcomes of) individuals born in the same year in different communities within the same district.
We find a clear and consistent negative relationship between post-natal positive rainfall exposure and our measures of mental health. In our benchmark specification, exposure to postnatal rainfall shocks increases average mental health scores by 15 percent (higher scores reflect a deterioration in outcomes) and increases the likelihood of depression by 5 percent, a more than 20 percent increase relative to the mean. Interestingly, and similar to same earlier studies, these effects are limited to women. While the explanation may be biological, it may also reflect endogenous responses by households which can be addressed through policy.
Since positive rainfall shocks are relatively common in Indonesia (25{ec5f16bc0d3188d22af0c52b0a003021539d5e8f81ad0cf83bf30b7820bde39f} of the sample experience a shock in the first 1,000 days post birth) and in the broader South East Asian region, this suggests a potentially large and understudied burden in the region arising from climate. This will likely increase in coming years as climate change is expected to increase both the variability of weather and the frequency of ‘extreme’ events.
We next examine the pathways suggested by the literature. We are able to rule out pre-natal stress to pregnant mothers, changes in household income, and seasonality. Our analysis suggests that changes in the disease environment may be a mechanism by which exposure to rainfall shocks affects subsequent mental health. If confirmed, this further underlines the importance of investments in basic public health and sanitation in developing countries.
Authors:
Mochamad Pasha, Consultant to the World Bank (Indonesia).
Marc Rockmore, Assistant Professor of Economics, Clark University
Chih Ming Tan, Professor and Page Endowed Chair in Applied Economics, University of North Dakota
Papers Cited:
Earlier version: CINCH+ Working paper No. 2018/05
“Fetal Origins of Mental Health; Evidence from Africa” Adhvaryu, Fenske, Kala, and Nyshadham