in behaviors that can affect pregnancy outcomes, not least because the intergenerational transmission of shocks results from a combination of biological and social mechanisms (Conti 2013). Although causality can be difficult to establish, and the consequences of prenatal behaviors on newborn health depend on many factors, such as the timing and extent to which they are incurred, or the quality of the inputs, there is evidence indicating that smoking, drinking alcohol and prenatal care can affect newborn and early child outcomes (East et al. 2017; Jewell 2007; e.g. Kramer 1987; Mwabu 2008; Popova et al. 2017; Rosenzweig and Schultz 1982).

A final aspect to emphasize is the possible heterogeneity of the impact of in utero shocks. The importance of education for health, including the relationship between parents’ and children’s, is well established theoretically (Grossman 2000) and empirically (Currie and Moretti 2003; Cutler and Lleras-Muney 2006; Cutler, Lleras-Muney, and Vogl 2008). In addition, education can mediate the responses to a stress shock. One possibility is that less-educated mothers, being poorer, have higher baseline levels of stress intensifying the biological reaction to a shock. Epidemiological literature shows a negative association between socioeconomic status and allostatic load (the cumulative ‘wear and tear on the body’ resulting from repeated or chronic stress), and to some degree with salivary cortisol levels (Dowd, Simanek, and Aiello 2009). Social studies also suggest a link between education and poverty with psychological well-being and mental health conditions (Bjelland et al. 2008; Hanandita and Tampubolon 2014; Haushofer and Shapiro 2016; Ozer et al. 2011). Another possibility is that education as a proxy for ‘ability’ is a mechanism mediating the behavioral responses to fear. In Becker and Rubinstein (2011), individuals with higher cognitive ability assess the risk (the probability of being directly affected) more accurately than those with lower cognitive ability and are consequently more likely to overcome the fear generated by indiscriminate violent events against civilians.<sup>16</sup> In this argument, mothers with higher education levels would experience lower stress and responsiveness to a violence shock than less-educated mothers. Finally, there can also be a direct income effect, whereby more educated mothers with higher incomes have more resources to spend to cushion or compensate the effect of a shock.

# **III.The shifting pattern of 50 years of war**

Colombia has one of the longest internal armed conflicts in the world. It has roots in a bipartisan confrontation period in the 1950s ( _La Violencia_ ), but its current form started the following decade with the emergence of guerrilla groups whose stated aim was to overthrow the state. It has been characterized as a struggle for local power, rather than as a separatist, religious or ethnic conflict. The main guerrilla groups operating through the period of analysis are FARC ( _Fuerzas Armadas Revolucionarias de Colombia_ ),<sup>17</sup> which was founded in 1964 and dismantled with a peace agreement in 2017, and ELN _(Ejercito de Liberación Nacional_ ).<sup>18</sup> Paramilitary groups emerged in reaction to guerrillas in the late 1980s as private self-defence armies with connections with drug cartels (Zelik 2015). Their umbrella organization, the AUC ( _Autodefensas Unidas de Colombia_ )

> 16 They find supporting empirical evidence, whereby the consumption of goods affected by terrorism (bus rides) bounces back for more-educated individuals but not for less-educated ones.

> 17 6,900 combatants demobilized but at its peak around 2002, it was estimated that FARC had between 16,000 and 20,000 combatants.

> 18Estimated to have about 1,300 combatants.

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