economic returns of poverty reduction programs, namely, microfinance and conditional cash transfer programs. The authors argue that poverty reduction programs were shown to have increased earnings by up to 18% for poor households in low and middle-income countries.<sup>31</sup>

# **5.3 Event Study Analysis**

This section presents the event study analysis of the results reported in the previous sections. A slightly modified version of the main regression equation is used by including a series of treatment exposure dummies with 1-2 year intervals, starting from 4 years prior to birth until the age of 8 years.<sup>32</sup> The omitted category for event time is exposure at age 9 years or above. Following Hoynes et al. (2016), the focus is on the event study coefficients inside the unbalanced endpoints of programs: initiated 2 years or more prior to birth, and age 9 years or more.

The event study analysis serves two purposes. First, it helps to identify the period in early life where the impact is the highest. Finding out the causal impacts of shocks at different points in the life cycle is difficult given the strong correlation of deprivation across the vulnerable periods in the life cycle (Maccini and Yang, 2009). One of the key insights from the research on child nutrition is the concept of “critical-period programming”, where environmental conditions in a certain sensitive period of life may have long-term, irreversible effects. While Barker (2000) stresses that nutritional deprivation _in utero_ permanently reduces body size in adulthood, more recent studies

> 31The results in the previous and the present section indicate that exposure to a midwife during early childhood significantly improves the outcomes for adult males, but not for adult females. Note that these results are consistent with a number of recent studies that find greater health and cognition impacts among adult males for early life interventions such as greater nutrition (Hoynes et al., 2016; Stein et al., 2006), quality childhood care (Garc ́ıa et al., 2017; Campbell et al., 2014), and malaria eradication (Venkataramani, 2012; Cutler et al., 2010; Rosenzweig and Zhang, 2013). Furthermore, the findings of increased earnings among males also are observed for a nutritional intervention in Guatemala (Hoddinott et al., 2008) and malaria eradication programs in India and Mexico (Halim et al., 2015). Given the weak evidence of discriminatory allocation of nutrition and educational investment for children in Indonesia (Kevane and Levine, 2000; Suryadarma, 2015), one can explore the biological evidence of greater sensitivity of males to the surrounding environment _in utero_ and early childhood as a likely pathway (Kraemer, 2000; Eriksson et al., 2010; Hoynes et al., 2016). For instance, males could benefit more from the midwifery services both in dimensions of physical health and cognition which translates into better adult outcomes along a number of dimensions. However, testing these different hypotheses would require at least detailed panel data on parental investments, cognition and a host of health outcomes, and job opportunities for men and women.

32 The event time takes a value of _−_ 1 for children born one year after the arrival of midwives. Children born two years or after the arrival of midwives are grouped as less than or equal to _−_ 2.

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