Season of Birth Impacts on Children in China∗
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The Winter's Tale: Season of Birth Impacts on Children in China∗ Pushkar Maitra,y Nidhiya Menonzand Chau Tranx April 2019 Abstract This paper examines the effect of season of birth on height and on cognitive and non-cognitive skills of Chinese children. We find that the child's season of birth has a significant impact on the height of girls aged less than 5 years in agricultural households: girls born in winter are 0.5 standard deviations shorter as compared to girls born in other seasons. We find, however, that this relative height differential does not translate to deficits in cognitive and non-cognitive skills when girls are adolescents aged 10{15 years. We show that compensating investments by parents, manifested through higher parental expectations on educational attainment for poorly endowed winter-born girls, may be an explanation for why the initial height disadvantage does not have persisting negative implications when girls are older. Key Words: Child Health, Cognitive and Non Cognitive Skills, Compensating Investments, Season of Birth, China JEL Codes: O15, I15, J13 ∗We thank Samia Badji, Diana Contreras Suarez, Joseph Cummins, Adeline Delavante, Umair Khalil, Claudio Labanca, Rigissa Megalokonomou, Russell Smyth and seminar and conference participants at Monash University, the Australian Development Economics Workshop (ADEW), the Italian Summer School in Development Economics (SSDEV), the Australian Health Economics Society (AHES) meetings, the PacDev meetings, and Williams College for comments and suggestions. The data are from the China Family Panel Studies (CFPS) funded by 985 Program of Peking University, and carried out by the Institute of Social Science Survey of Peking University. The usual caveat applies. yDepartment of Economics, Monash University, Clayton Campus, VIC 3800, Australia. Email: [email protected] zDepartment of Economics, MS 021 Brandeis University, Waltham, MA 02453, USA. Email: [email protected] xDepartment of Economics, Monash University, Clayton Campus, VIC 3800, Australia. Email: [email protected] 1 Introduction This paper examines the effect of season of birth on long-term health, and on cognitive and non- cognitive ability of Chinese children. There is now a growing literature that examines the effects of early childhood conditions on outcomes later in life. Specifically, it is argued that the time of the year when a child is born matters. The literature has documented that time of birth and neonatal health can affect the outcomes of very young children including infant mortality (Breschi and Livi-Bacci, 1997), their health as adults (Weber et al., 1998), susceptibility to diseases and disabilities (Muhuri, 1996), their life span (Doblhammer and Vaupel, 2001), and cognitive ability (McGrath et al., 2006, Venkataramani, 2012, Figlio et al., 2014). The economics literature from both developed and developing countries suggests that the time of the year the child is born impacts human capital development. For example Angrist and Kruger(1991) finds that in the US, children born during the first quarter of the year have lower average levels of education than children born later in the year. Almond and Mazumder(2011) finds that in-utero exposure to Ramadan (the Islamic month of fasting) results in lower birth weight and a higher probability of long term disability. Using data from India, Lokshin and Radyakin(2012) finds that children born during the monsoon months have lower anthropometric scores compared to children born in the post-monsoon and winter months. Shah and Steinberg(2017) finds that more early-life rainfall is associated with higher test scores in both math and reading. They also find that more rainfall during school years (particularly ages 11{13) lowers total years of schooling. We examine the impact of season of birth on children born in agricultural and non-agricultural households in China, after ruling out selection into season of birth (i.e., after ensuring that births are not timed). Much of the literature on the effect of season of birth on child outcomes has focused on the effect of the monsoon (for example Maccini and Yang, 2009, Tiwari et al., 2017).1 However, depending on the context, births in other seasons of the year may also have adverse implications for children. For instance in environments where food cannot be stored easily, winter 1In developing countries like China where agriculture is an important source of livelihood, the monsoon season is crucial and can affect child outcomes in multiple ways. By influencing agricultural production, the timing of the monsoon is correlated with resource availability within the household, which can positively influence the health of children. However, the monsoon is also associated with an enhanced disease environment, which can have a negative effect on the health of children in agricultural households. 1 is often a season of shortages, and this is particularly true in China.2Brown et al.(2011) argues that during specific events and festivals, poor households in China increase their spending on socially observable goods as a channel of status seeking. The Lunar New Year, which is typically in winter, is one such event. By limiting liquidity, such spending could further exacerbate resource constraints within households, with adverse effects on child health and development. We find that relative to girls born in winter, girls in agricultural households born in the non- winter seasons (pre-monsoon, monsoon and post-monsoon) have significantly higher height-for- age z-scores (HAZ), the widely accepted proxy for long-term health.3 The relative effect is the strongest and most persistent for children born in the post-monsoon season. There is no effect of season of birth on birth weight, which indicates that the season of birth effect on health is not due to what happens in-utero; rather it may be the result of circumstances the household faces after the child is born. An explanation is that the early nutritional deprivation that girls may face (in the period after being born and weaned) is exacerbated in winter months when households are particularly resource-constrained. We further investigate whether such initial disadvantages have lasting impacts. We find that there is little effect of season of birth on the cognitive and non-cognitive ability of these children in adolescence. In particular, while girls in agricultural households born in winter have lower relative HAZ as of age 5, this disadvantage does not translate to lower cognitive or non-cognitive development in a sample of 10{15 year old winter-born girls. We hypothesize that this is because conditional on observed health, there are compensating investments on the part of parents so that early childhood disadvantages do not have lasting consequences.4 We find that such compensating investments take the form of parents investing additional time and resources in girls born in winter. These results corroborate the findings of Leight et al.(2015) who, use the Gansu Survey of Children and Families (GSCF) survey and, show that the effect of early life shocks on cognitive skills of children declines over time. They argue that compensatory strategies by parents contribute to this 2Figure A1 presents the crop calendar for China. This shows that there is very little agricultural produc- tion/activity during the winter months. 3See discussion in Section3 on the use of HAZ as a measure of long term health of children. 4See Cunha et al.(2010) and the references cited therein for more on the issue of compensating investments by parents. 2 decline in the impact of early life shocks. Our results are consistent with an income equalization hypothesis and with the notion of dynamic compensatory investments on the part of parents, who, as demonstrated in other contexts, spend more inputs on these relatively underprivileged children (Behrman and Rosenzweig, 2004, Almond and Mazumder, 2013, Adhvaryu et al., 2018, Leight and Liu, 2018). We use parental expectations on the educational attainment of children, conditional on observed health and other individual and household characteristics, as a proxy measure for why parents may engage in compensating behaviour. Parental expectations can be a key indicator of parents' involvement and investments in children's education (Fan and Chen, 2001), and can potentially be a crucial determinant in forming children's attitudes towards education (Wood et al., 2007). The existing literature posits a significant positive correlation between parent's expectations and children's educational achievement through provision of a supportive and emotionally inspiring environment (Neuenschwander et al., 2007). Leight(2017) examines allocation of educational expenditures to children and finds that these expenditures are directed to the child with relatively lower physical endowments.5 There is evidence therefore that parents use educational funding to compensate for differences in their children's health. We find that parents from agricultural households hold higher educational expectations for daugh- ters born in the winter as compared to those born in the non-winter seasons. A reason may be that parents believe that because of their relative initial health advantage, girls born in the non-winter seasons are better off when it comes to physically intensive labor market work. But daughters born in winter who are seen to be relatively disadvantaged in terms of health are encouraged to invest in education so that they may gain remuneration from more mentally demanding tasks when adults. This is in the spirit of the brain vs brawn hypothesis, but within children of the same gender (Pitt et al., 2012). We find that parental expectations are positively correlated with educational expenditure and negatively correlated with hours of housework for winter-born girls in agricultural households. Our results are also consistent with those of Leight(2017), again though within gender. We hypothesize that such differential investments lead to catch-up (of winter-born 5Leight(2017) uses data from the GSCF survey, i.e., from a specific province of China.