to an additional fatality during the last pregnancy trimester reduced birthweight by 2.1 gr<sup>6</sup> and that the odds of a child being born with low birthweight increase if the mother was exposed to violence in the first trimester. Valente’s (2015) was the first study to explicitly address the concerns about survival selection and gender-specific effects in the context of violence shocks. Using DHS data for Nepal, she finds that violence exposure in utero increases fetal deaths<sup>7</sup> and that this is more pronounced for boys, as evidenced by a fall in the gender ratio at birth. However, there was not an increase in the probability that a baby was considered small at birth nor a reduction in neonatal mortality,<sup>8</sup> as would be consistent with a selection effect.<sup>9</sup> Still, the results contradict the earlier studies in Colombia and the West Bank and Gaza, as babies exposed to conflict during gestation were not systematically in worse health at birth. A suggested explanation for this difference is that the selection effect may be weaker (or the scarring effect stronger) in relatively more developed countries. The recent study by Dagnelie, Luca, and Maystadt (2018) also shows evidence of a stronger selection effect in a poor country, the DRC. This is seen in a reduction in the gender ratio at birth, a decrease in aggregate district-level number of male births and a lack of change in boys’ health, as captured by a fall in infant mortality of girls but not of boys. In contrast, QuintanaDomeque and Ródenas-Serrano (2017) find that in Spain, exposure to ETA bomb casualties in the first trimester of pregnancy had a small negative effect on birthweight despite an increase in fetal deaths (stillbirths).<sup>10</sup> This work in a developed country still leaves a gap in the evidence with respect to the strength of the selection effect in middle-income developing countries.

Methodologically, this literature shares the use of geographical and time variations in violence to identify the intended effect.<sup>11</sup> Most of these previous studies use measures of violence based on victims, such as the number of conflict-related fatalities or bomb casualties. In contrast, here, as in Dagnelie, Luca, and Maystadt (2018),<sup>12</sup> I choose violence events. Victim-based measures are more likely to capture the underlying intensity of the conflict in an area and are thus more likely to be endogenous. My approach, as will be explained in the methodological section, is to focus on a particular type of event —violent attacks against civilians— that is a better reflection of an exogenous local-violence shock, and less of the underlying violence intensity.

One aspect shared in the literature is the focus on aggregate violence exposure rather than on individual victimization. This emphasizes the role of stress as the most likely channel between

> 6 However, the effect is not statistically different from zero in a restricted sibling sample with a substantially reduced sample of approximately 500 births (40\% of the original sample).

> 7 Although she finds a negative effect on stillbirths, the increase in miscarriages is larger and the overall effect on fetal deaths is thus positive.

> 8 Also, the interaction with gender did not show a stronger positive health effect for boys as would be expected if the strongest had survived to birth.

9 Although there can be a selection of the babies surviving into late pregnancy as shown by the increase in miscarriages and the small decrease in stillbirths.

> 10 They use VRS data (1980-2003) and their most complete specification uses fixed-effects for province, time (month-year of conception) and province trend (the interaction between province and time). The size of the effect in this specification was of - 0.28 gr per additional casualty.

11 This differs from the approach used by other studies analysing the effects of war on human capital (e.g. Akresh, Lucchetti, and Thirumurthy 2012; Weldeegzie 2017) that rely on comparisons of conflict-affected areas with those where the conflict was absent, before and after a war, as this setup may not be appropriate for countries where violence is geographically widespread and distinguishing between affected and non-affected areas is not straightforward, or where the ongoing nature of the conflict complicates the determination of the before and after periods, as in fact is the case in Colombia. (For instance, 67\% of the Colombian municipalities are classified by the local research centre CERAC (Restrepo et al. 2014) as experiencing ‘interrupted’ conflict during the 2000s, which means that the presence of armed groups has been sporadic.) 12 To address this concern, (Dagnelie, Luca, and Maystadt 2018) use a mineral price index as an instrument variable for local violence intensity.

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