metadata: authors: 0: author: Rodriguez Takeuchi,Laura Kiku
count: Colombia
docna: 0: docna: Violence and Newborn Health : Estimates for Colombia
docty: Policy Research Working Paper
subtopic: Health Care Services Industry,Educational Sciences,Armed Conflict,Gender and Development,Law and Justice Institutions
teratopic: Industry,Education,Conflict and Development,Gender,Law and Development
abstracts: cdata!: This paper examines the relationship
            between maternal exposure to violence during pregnancy and
            newborn birthweight. The paper exploits variation in the
            timing of exposure and in the geographic location of
            expectant mothers across Colombian municipalities. Exposure
            to violence in early pregnancy had a large negative impact
            on birthweight, primarily for boys, and the effect was
            mitigated by their mothers' education. Girls were
            affected mainly by shocks in later stages of gestation.
            Furthermore, their mothers were more likely to engage in
            potentially harmful behaviors during the pregnancy. This
            evidence exposes the importance of parental responses in
            shaping the effect of exposure to violence on newborn health.
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repnme: repnme: Violence and Newborn Health : Estimates for Colombia
display_title: Violence and Newborn Health :
            Estimates for Colombia
listing_relative_url: /research/2020/09/32371699/violence-newborn-health-estimates-colombia
topicv3: Education m1327048 470,Political Violence and War m1327310 2462,Gender m1327621 615,Mortality m1504365 3661,Health m1504661 3480
publishtoextweb_dt: 2020-09-01T00:00:00Z
historic_topic: Industry,Education,Conflict and Development,Gender,Law and Development
origu: EFI-MNA-POV-Poverty and Equity (EMNPV)
no_of_pages: 41
author_keys: 0: author_key: 1816488
model_extractions: Policy Research Working Paper 9377 Violence and Newborn Health Estimates for Colombia _Laura Rodríguez_ Poverty and Equity Global Practice September 2020
Policy Research Working Paper 9377

# **Abstract**

This paper examines the relationship between maternal exposure to violence during pregnancy and newborn birthweight. The paper exploits variation in the timing of exposure and in the geographic location of expectant mothers across Colombian municipalities. Exposure to violence in early pregnancy had a large negative impact on birthweight, primarily for boys, and the effect was mitigated by their mothers’ education. Girls were affected mainly by shocks in later stages of gestation. Furthermore, their mothers were more likely to engage in potentially harmful behaviors during the pregnancy. This evidence exposes the importance of parental responses in shaping the effect of exposure to violence on newborn health.

This paper is a product of the Poverty and Equity Global Practice. It is part of a larger effort by the World Bank to provide open access to its research and make a contribution to development policy discussions around the world. Policy Research Working Papers are also posted on the Web at http://www.worldbank.org/prwp. The author may be contacted at lrodrigueztak@worldbank.org.

_The Policy Research Working Paper Series disseminates the findings of work in progress to encourage the exchange of ideas about development issues. An objective of the series is to get the findings out quickly, even if the presentations are less than fully polished. The papers carry the names of the authors and should be cited accordingly. The findings, interpretations, and conclusions expressed in this paper are entirely those of the authors. They do not necessarily represent the views of the International Bank for Reconstruction and Development/World Bank and its affiliated organizations, or those of the Executive Directors of the World Bank or the governments they represent._ Produced by the Research Support Team
# **Violence and Newborn Health: Estimates for Colombia**

Laura Rodríguez<sup>1</sup>

**JEL codes** : I10, J13, J16

**<mark>Keywords</mark>** <mark>: Violence; Pregnancy; Birthweight; Newborn health.</mark>

1 <u>lrodrigueztak@worldbank.org. World Bank, Poverty and Equity Global Practice. The work for this paper was</u> conducted while at the Department of Economics of The University of Manchester. The author is grateful for financial support from the Department of Development and Alumni Relations and the Department of Economics at the University of Manchester. The findings and conclusions in this paper are those of the author and do not represent the views of The University of Manchester nor of the World Bank and its affiliated organizations. The author is grateful to Katsushi Imai, Kunal Sen, Martin Foureaux-Koppensteiner and Peter Backus for the support, discussions and suggestions, as well as to participants at seminars at the University of Manchester, the Nordic Conference of Development Economics 2018, LACEA-LAMES 2018, Universidad EAFIT, Universidad del Rosario, iHEA 2019 and ESPE Annual Conference 2019, whose questions and comments were particularly insightful and helped to improve the paper. Special gratitude is due to Andrés Suárez for his time and willingness to discuss the CNMH’s conflict data, and to the CNMH for making it available. Additional thanks are due to William Wiseman and Jose Antonio Cuesta for their comments. All errors are my own.
# **Violence and Newborn Health: Estimates for Colombia**

# **I. Introduction**

Armed conflicts can reverse development (Collier 2004; The World Bank 2011), but wars cause more than physical destruction, leaving many indirect victims, some yet to be born. Important consequences can arise from stress created by the occurrence of violence in the locality where people live, and this study aims to capture one such effect. I focus on the effects of war violence by studying whether the exposure of pregnant women to violence affects their newborns’ health.

The literature examining the importance of the prenatal environment and shocks experienced during gestation on health and later-life outcomes is large (Almond and Currie 2011). The main contribution of the paper is to strengthen the existing empirical evidence with respect to the impact of conflict-violence exposure in utero on newborn health. Earlier studies (Camacho 2008; Mansour and Rees 2012) found a strong scarring of the health of newborns exposed to violence during gestation. These, however, overlooked the importance of gender differences in the developmental process and in the responses to prenatal shocks (Valente 2015). More recent studies by Valente (2015) in Nepal, and Dagnelie, Luca, and Maystadt (2018) in the Democratic Republic of Congo (DRC) found evidence of higher fetal mortality, especially among boys, and an absence of worse health outcomes for the surviving newborn boys exposed to violence during gestation. Contrasting this evidence with that coming from early studies, the hypothesis advanced was that the selection effect would be likely to dominate in more deprived contexts, such as in these relatively less developed countries, where baseline health is poor (Almond and Currie 2011; Valente 2015). There is still a gap in empirical evidence, however, on whether this would hold in relatively more prosperous developing countries, or whether there are additional non-biological factors that shape this relationship. With this in mind, this study re-examines the case of Colombia, initially addressed by Camacho (2008), disaggregating the analysis by gender and checking for survival bias. The study also extends the analysis in two important ways. Firstly, a contribution is made by analyzing the within-country heterogeneity in the effect given by the maternal human capital. Secondly, as it is known that disparities in health are transmitted across generations through biological and socio-economic mechanisms (Conti 2013), the study explores the role of behavioral channels as a potential transmission mechanism for the intergenerational effect of violence exposure.

Colombia has a long-standing internal armed conflict which has been characterized as a struggle for local power. The hotspots of violence and the strategies used by different armed groups involved in the conflict have been varied. The violence intensity has been characterized by subnational heterogeneity. In this context, the identification strategy follows the literature in exploiting geographically and time differentiated violence exposure by municipality (the local area unit used here) and date of occurrence. Unlike previous studies, which predominantly used violence measures based on the number of victims, I chose a measure of events —violent attacks against civilians— to capture a violence shock. Victim-based measures tend to reflect the underlying intensity of the conflict in an area and thus to be correlated with underlying local characteristics that may also determine health outcomes. On the other hand, the exact timing and location of an attack against civilians is, by definition, uncertain, even in areas with known presence of armed groups. Moreover, although these attacks do not always result in casualties and the likelihood of 2
being a direct victim is considerably low, the fear that these events arouse in the general population enables them to result in important impacts (Becker and Rubinstein 2011). Therefore, even in the context of sustained armed conflict this is a better measure of a local shock.

In addition to the variation in the occurrence of violent events at the municipal level, there is exogenous variation in the individual violence exposure resulting from the gestation stage of pregnancies within municipalities when such an event occurs. To obtain this high-frequency variability in the data, I link historical records of violent attacks by municipality of residence of the mother and month of occurrence of the events with the month of gestation coming from household survey data. Violence data are compiled by the _Centro Nacional de Memoria Histórica_ (CNMH),<sup>2</sup> and household survey microdata with information about pregnancies and birth outcomes come from three rounds of the Demographic and Health Surveys (DHS).<sup>3</sup> The impact of violence is assessed on weight at birth and neonatal mortality, measures that reflect the cumulative pregnancy conditions. Birthweight influences a wide range of outcomes over the life cycle, from adult disease prevalence to educational attainment, labor market outcomes, earnings and social status, highlighting its relevance (Black, Devereux, and Salvanes 2007; Case, Fertig, and Paxson 2005; Currie and Hyson 1999; Johnson and Schoeni 2011).

Overall, I found a negative effect of exposure to violence on the health of newborn babies, but with distinctive gender patterns. For boys, there was a scarring effect of exposure to a violence shock during early-pregnancy, reflected in a birthweight reduction of about 40 grams (gr), on average, and an increase in the probability of being born with low birthweight. The effects were much stronger for the boys of uneducated mothers, diminishing by 29 gr for each additional year of education of the mother. Despite these findings, I did not find strong evidence of an overall or predominantly male increase in fetal mortality associated with exposure to early-pregnancy shocks, even for the children of less-educated women, who are likely to be at the bottom end of the health distribution. In sum, unlike earlier findings for Nepal and DRC, the selection effect in Colombia appears to be dominated by the scarring effect.

These results contrast with the findings for baby girls. They appear to be stronger against earlypregnancy shocks, but those exposed to violence after the first trimester had higher probability of being born with low birthweight and of dying in the neonatal period. These effects were also driven by those whose mothers had no schooling. The differentiated gender pattern in the results, especially the lower resilience of boys to early-pregnancy shocks, is consistent with biomedical explanations about fetal responses to shocks (Kraemer 2000), whereby females are more adaptable to prenatal adversity and changing environmental conditions and males are less able to adjust and are thus at greater risk of mortality and morbidity.

However, if biologically girls should be more resilient to in utero shocks, what can explain the deterioration of health found for those exposed to violence in late pregnancy? Some additional results of this study provide suggestive, although not definitive, evidence that changes in maternal behaviors during pregnancy for women exposed to violence played a role in the worsening of newborn girls’ health. Women who were pregnant with a girl and were exposed to violence at this time were less likely to receive prenatal care and be vaccinated against tetanus during pregnancy,

> 2 National Centre of Historical Memory.

> 3 _Encuesta Nacional de Demografía y Salud_ in Spanish.

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and more likely to drink alcohol. Although judgement on the role of these mechanisms connecting violence shocks and newborn health is inevitably speculative, the evidence here exposes the importance of behavioral responses, in addition to the purely biological effects induced by violence-related stress.

The next section reviews empirical studies in economics examining the fetal origins hypothesis and particularly those that have specifically addressed war-violence shocks. Section III gives a brief overview of the Colombian conflict. Section IV describes the data and presents the methodological details of the analysis. The results are presented in the following section. The conclusion at the end summarizes and highlights avenues for future research.

# **II. Literature review**

The fetal-origins hypothesis states that shocks to the environment in utero alter the physiology and metabolism of the fetus, with effects apparent at birth<sup>4</sup> and lifelong consequences (Almond and Currie 2011; Johnson and Schoeni 2011). While this literature started in the biomedical field, the economic discipline has contributed in two main fronts, as described in Almond and Currie (2011). First, it formalized the notion of the observed net effect of an in utero shock depending on the balance of two opposing forces. On the one hand, the scarring effect is the deterioration of fetal health produced by the shock. On the other hand, if there is higher fetal mortality at the lower end of the fetal health distribution, the sample of live births for whom the effect of the shock is measured would be smaller and selected; the culling or selection effect refers to the better average observed health in this surviving cohort. Whether the survivors are healthier or weaker has implications for explaining inequality patterns of later-life outcomes. The second contribution of the economic discipline to this literature has been empirical, broadening the variety of shocks analyzed. A subset of this literature focuses on violence. Some studies look at criminal violence (Dustmann and Fasani 2016; e.g. Foureaux-Koppensteiner and Manacorda 2016), but I concentrate the review on those emphasizing violence in conflict-affected countries.<sup>5</sup> I also concentrate on the short-term impacts of violence exposure in utero, although other studies (e.g. Akresh et al. 2012; Akresh, Lucchetti, and Thirumurthy 2012; Tranchant, Justino, and Müller 2020) indicate that in utero effects can last through childhood, and that there are negative health consequences of exposure to war violence at other stages in life.

Camacho (2008) analyzes the Colombian case using birth records from the Vital Registration System (VRS) (1998 to 2003) and municipal landmine explosions data. She finds that a landmine explosion occurring during the first trimester of pregnancy in the municipality where the mother resides is associated with a reduction in birthweight of 8.7 gr, while there was no effect for explosions in the second or third trimesters. Using a similar empirical specification, Mansour and Rees (2012) look at the al-Aqsa Intifada in the West Bank using DHS data and district-level fatalities caused by Israeli security forces as the violence measure. The authors find that exposure

> 4 For instance, fetal alcohol syndrome, wherein the newborn's facial features reflect the mother's alcoholism, or stunted or missing limbs associated with the intake of thalidomide, a once commonly prescribed medicine for morning sickness (Almond and Currie 2011).

> 5 This also excludes studies that analyzed a one-off, large-scale event (e.g. the September 11 attacks (Currie and Schwandt 2016)).

4
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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violence and newborn health. The effects of increased stress during pregnancy on the offspring have been experimentally tested in animals, but for clear ethical reasons, studies in humans rely on natural experiments using exogenous variations in stress. Animal experiments show that the offspring of mothers subject to higher stress hormones or to stressful conditions while pregnant have lower weight and behavioral changes (Schneider 1992; Schneider, Coe, and Lubach 1992; Weinstock 2008; Welberg, Seckl, and Holmes 2001), and the human body’s response to stress, first described in biomedical research by Hans (1936), would point to a similar effect on humans. This biological response to stress is mediated by cortisol, which increases sugar in the blood, suppresses the immune system, disrupts the digestive and reproductive systems and regulates the growth process, and by adrenaline, which increases the heart rate and blood pressure. The aim is to increase the body’s energy supplies and limit non-essential functions. Because fetuses are exposed to the stress hormones from their mothers, especially in early-pregnancy,<sup>13</sup> and because of the role of cortisol during the pregnancy, even a transient stress shock in a sensitive period can harmfully impact the fetus development and even alter the expression of certain genes.

Stress hormones signal an unfavorable environment for the fetus; the placenta reacts to maternal stress hormones by stimulating the release of corticotrophin-releasing hormone (CRH),<sup>14</sup> which advances the ‘placental clock’ and results in premature birth. In other words, the stress signals trigger an accelerated metabolism and maturation of the organs so that the fetus has greater chances of survival by escaping as quickly as possible from the harmful host environment. There is a tradeoff: the baby born preterm is overall less mature and smaller at birth than one who developed at a normal rate (Sandman and Davis 2012). Maternal stress may also result in fetal exposure to excess cortisol by down-regulating the activity of binding proteins and enzymes, particularly 11β-HSD2, in the placenta (Glover et al. 2009). Because fetal exposure to cortisol varies naturally during the course of the pregnancy,<sup>15</sup> this response to an adverse environment is more likely to be prompted in early stages of gestation (Pike 2005). It also varies by gender as the female placenta has higher activity of 11β-HSD2, which prevents cortisol from crossing the placental barrier, and hence, it is more responsive to changes in maternal cortisol concentration. This makes female fetuses more adaptable to changing conditions (Sandman and Davis 2012).

Responses may be triggered even when the stressor is indirect. This is evident with indiscriminate attacks against civilians, where the actual risk of direct victimization is low but the high perceived risk can be in itself enough to trigger responses in the wide population (Becker and Rubinstein 2011). The responses can also be behavioral; a growing strand of literature has drawn attention to changes in behaviors for populations exposed to war. Studies show that the experience of war increases inter-group cooperation, altruism and political participation, but reduces cooperation with outsiders (Bellows and Miguel 2009; Blattman 2009). Results from field experiments also show that individuals in communities affected by violence seem to be more risk-seeking and have higher discount rates (Voors et al. 2012), although those who are directly victimized show more risk-aversion (Moya 2018). This literature brings the question of whether there are such changes

> 13 Fetuses do not produce cortisol until around the fifth month of pregnancy.

> 14 The synthesis of cortisol is stimulated by the release of CRH in response to stress.

> 15 Placental CRH exponentially increases in the second half of the pregnancy, while placental 11β-HSD2 increases as gestation progresses and then falls abruptly near term. The combination of these processes results in an increase in fetal exposure to cortisol towards the end of gestation, which is necessary to ensure the maturation of lungs, the central nervous system and other organs in the fetus, as well as to precipitate birth when the time comes, but which can be detrimental in excess or earlier than normal.

6
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.

7
demobilized in 2004<sup>19</sup> but factions re-emerged as emerging criminal bands ( _Bacrim),_ which are considered organized crime groups seeking control of drug and illicit goods’ traffic (Zelik 2015).

Even though the conflict has reached a large part of the country, the violence and its intensity have been geographically heterogeneous. Moreover, it has had periods of lower and higher intensity, and shifting ‘hotspot’ areas. Between 1965 and 1981, the intensity of violence was low and stable. This steadily increased and peaked between 1996-2002, falling again thereafter (CNMH 2013). In recent years, relatively peaceful periods associated with ceasefires during the peace negotiations with FARC were followed by violence escalations when ceasefires were broken. After FARC’s demobilization, violence has intensified in strategic, coastal and border areas where dissident and rival groups battle for the control of vacated territory, drug cultivation and trade corridors (International Crisis Group 2015, 2017). Geographically, in the 1990s the conflict spread from the areas of historic origin of guerrillas in peasant colonization areas to large parts of the country, even those integrated into national markets and politics. The late 1990s saw the territorial expansion of the conflict and the consolidation of armed groups in the strategic corridors for drugs and war, especially those in the corridor between the inland-Caribbean region and the Andean region, and that in the low Putumayo and south-eastern Orinoquía. The early 2000s, marked by the military offensive against guerrillas and the paramilitary demobilization, saw a retreat of armed groups to the areas of historic presence, but also to new peripheral areas, particularly along the Pacific southwest (Vásquez 2014). These patterns respond to aspects such as the limited state presence in certain areas of the country, the struggle for control of strategic and war-economy areas, and the pressures from the army’s military strategies (González, Bolívar, and Vásquez 2003; Gutiérrez and Sánchez 2006). The peak of violence in the late 1990s, for instance, resulted from a mix of the military strengthening of guerrillas, the expansion of paramilitary groups, the weakness of the state, the economic crisis and the reshuffling of drug cartels’ structure (CNMH 2013).

Different armed groups have preferred different types of violent actions, although these have also varied though time. In the case of violent attacks against civilians, the main perpetrator since the mid-1990s have been guerrilla groups, though that does not imply this was the main type of violence they perpetrated. Between the late 1980s and 1993 attacks were highly associated with drug cartels,<sup>20</sup> but since then, the cartels favored a low profile, which resulted in a reduction in their use, and a parallel pick-up of this strategy by guerrilla groups (CNMH 2013). The peak of violent attacks in the early 2000s was linked to the guerrilla’s desire to demonstrate their growing power, as well as being a contention strategy against the paramilitary growth and, later on, the state’s military recovery (CNMH 2013). These attacks have been, with some notable exceptions, aimed at the local sphere.

# **IV. Empirical strategy**

# **A. Violence data**

A key challenge for identifying the effect of violence is to find a measure of a _shock_ instead of one reflecting persistent _levels_ of violence in a municipality. Violent attacks against civilians have

> 19 31,000 combatants demobilized but former paramilitary leaders have stated that these numbers were inflated and that the actual number of combatants was about half.

> 20 Particularly the Medellin cartel.

8
various characteristics that suit this purpose. They highly affect civilians at the local level,<sup>21</sup> but direct victimization is rare. Instead, the use of explosives and the surprise element makes them visible and generates fear among the wider (local) population.

I define these attacks following the CNMH as ‘ _all indiscriminate attack carried out with explosives, against civilian objectives, in public places, with the aim of causing high lethality and devastation upon the civil population’_ (CNMH 2013, 101). This definition contains the following key elements: 1) the events are indiscriminate rather than directed against a particular target, 2) they are not armed interventions<sup>22</sup> and the use of explosives implies some degree of absence or distance of the perpetrating actor from the scene, 3) the objectives are civilian, not military, 4) they happen in visible and densely populated places rather than in private spaces or remote rural areas, 5) the intent is to affect a large number of people/civil goods to show the perpetrator’s potential power of devastation.<sup>23</sup> It can be argued that these events are more unpredictable than other conflict events such as military attacks or battles. Armed groups use attack like these to generate fear in the civil population by showing their potential power of devastation against random individuals and places. Even in areas where the presence of armed groups is known, there is uncertainty about exactly where and when an attack may take place.

The measure of violence in Camacho (2008) —landmine explosions— may also appear to be fitting, but it is more akin to a victim rather than an event count, as there is almost always a victim who triggers the explosive. There are other issues which make landmine explosions problematic as a measure of a violence shock. The date of occurrence is delayed with respect to when the mine was planted, although this is a minor concern if the interest is in the stress effect. More importantly, minefield are heavily concentrated in a few municipalities and locations are strongly correlated with the conflict intensity and the local presence of armed groups.<sup>24</sup> Finally, although landmine victims are not targeted in advance, they have a specific profile: victims are disproportionately children and people who work as manual eradicators of illicit crops, as well as indigenous people (CNMH and Fundación Prolongar, 2017). Moreover, landmines they are almost exclusively placed in rural areas (98% of them, according to the CNMH and Fundación Prolongar (2017)), which means that their visibility and potential impact is low in urban parts of the country. This means that they can be perceived as less indiscriminate, limiting the fear generated in the wider population as those falling outside of these profiles or living in urban areas may not feel at risk. For these reasons, I prefer violent attacks over landmine explosions as a measure of violence events.

The records of violent attacks for this study come from the compilation by the CNMH for its 2013 report _Basta Ya! Memories of War and Dignity_ . Since these records stop in 2012, I update them until March 2016 going back to the original source, the _Centro de Investigación y Educación_

> 21 Combats or battle deaths measures do not fit the profile of modern armed conflicts, where most of the violence is not the product of military confrontations, rather aims to control population and territory and is targeted towards civilians (Kaldor 2006, 2013).

> 22 These would be attacks against a population, colloquially referred to as guerrilla incursion ( _toma guerrillera_ ).

> 23 This definition shares various components with, for instance, the one used in the United States: ‘Premeditated politically motivated violence perpetrated against non-combatant actors by sub-national groups or clandestine agents, usually intended to influence an audience’ (U.S. Department of State 1983, in Becker and Rubinstein 2011).

> 24 For instance, there is a strong temporal correlation between landmine explosions and conflict battles, and a geographic correlation with the municipalities where there is a strong offensive against guerrillas or where there are heavy territorial disputes; this is because the logic behind the use of landmines in Colombia is to halt or delay the actions of the military forces against guerrilla groups and to defend territories where armed groups are at risk of losing dominance (CNMH and Fundación Prolongar (2017).

9
_Popular_ (CINEP) _Noche y Niebla_ online database of human rights and political violence events, following the criteria and definition of the CNMH. The data exclude attacks perpetrated by criminal gangs or by the state’s armed forces, but nonetheless, these attacks in Colombia since the mid-1990s have been almost exclusively a strategy used by guerrilla groups.

The variation across time and space of violent attacks against civilians in the country is depicted in Figures 1 and 2. In the first, darker shades indicate a higher number of attacks through the period of analysis (1999-2016). Except for the south-east of the country, the most remote and low-density populated region,<sup>25</sup> the occurrence of attacks is scattered around the country. The map also shows their rarity, as most municipalities did not experience any attack in 16 years. Figure 2 shows the evolution of attacks by month of occurrence. There are more occurrences in the mid-2000s and less towards the end of that decade, coinciding with the pattern of conflict intensity in the country.

In the municipalities included in DHS (487 across the three survey rounds), there were 49 attacks in the period of study occurring in 29 different municipalities; that is, approximately 6% of the municipalities in the sample experienced at least one attack between February 1999 and March 2016. The recurrence of attacks in a municipality is low: ten of them experienced more than one attack in the period, and Tumaco, in the Pacific south-west, and Bogotá, the capital, had the highest occurrence with six and five attacks respectively. Not all events resulted in victims; in 23 attacks there were no fatalities and in 17 there were no wounded people. This reinforces the idea that the fear of potential devastation can be larger than the immediate effect on human lives.

# **B. Pregnancies and births data**

Violence data by municipality and month of occurrence are matched to household survey data from the Colombian DHS on the month of pregnancy (then aggregated and reported by trimester) and the municipality of residence of the mother. DHS are coordinated nationally representative crosssection surveys conducted in developing countries, which collect detailed information from women in reproductive age (13-49 years old in Colombia) and their households. These surveys include the history of live births in the five years before each survey. I use the V, VI and VII survey rounds (corresponding to 2005, 2010 and 2015),<sup>26</sup> which together account for live births occurring between November 1999 and March 2016 (pregnancies starting in February 1999).

DHS also include the characteristics of children, including their weight at birth, the main measure of newborn health used here. This is the most widely used measure in the literature to capture the fetal environment and has also been used to show the effects of early conditions later in life. Other measures of newborn health are underdeveloped and have not become widespread (Conti 2013). The main general limitation of DHS data is the potential missing birthweight information.<sup>27</sup> All results in the chapter need to be interpreted bearing this data restriction in mind. I also use neonatal mortality (death before the 28th day of life) as a complementary measure of newborn health, as

> 25 This region is also mostly dominated by the Amazon rainforest. DHS are representative of 99% of the country and the uncovered areas are disperse rural areas in this part of the country.

> 26 DHS surveys have been conducted in Colombia since 1986 but earlier rounds lack some crucial information for this study, particularly about pregnancy or publicly released identifiers to match municipalities with external data sets.

> 27 The child’s length at birth or the mother’s assessment about the relative size of their child (smaller/larger than average) can be used to alleviate the reporting problem. In our data, however, the reporting of length is even lower than that of birthweight, and there is no data collected about the baby’s relative size.

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this indicator is also reflective of the prenatal, birth and early neonatal conditions, with earlier neonatal deaths being more closely associated with the pregnancy environment.<sup>28</sup> The long span and high frequency of the data allows for the variability in the exposure to violence during gestation. In this study, the gestation period starts at the conception date and ends at birth. To estimate the beginning of the gestation period -- the date of conception-- I subtract the pregnancy length from the date of birth.<sup>29</sup> The pregnancy length is reported in the Colombian DHS and corresponds to the time elapsed between the first day of the last normal menstrual period of the woman and the delivery date.<sup>30</sup> Since conception usually occurs about two weeks after the last menstrual period, I subtract two further weeks from the reported pregnancy length to more accurately capture the gestation period.<sup>31</sup> This period is divided into trimesters, which are calculated by sequentially adding three-month intervals from the estimated conception date until birth.<sup>32</sup> The last trimester can thus be shorter than three months.

Exposure to violence in utero is reported in Table 1. Of pregnancies ending in a live birth, 3.29% were exposed to a violent attack against civilians at any point during gestation. In each trimester about 1% of fetuses were exposed to an attack, with a slightly higher share exposed in the first trimester (1.31%). Most pregnancies were exposed only once; less than 7% of the exposed pregnancies experienced two attacks and none were exposed more than twice. Because of this, in the analysis I use a dummy variable of exposure.<sup>33</sup>

# [Table 1 here]

# **C. Specification**

I exploit the geographic — by municipality — and temporal variation — by date of occurrence and gestational age — of violent attacks against civilians to identify the effect of violence on newborn health. One key challenge to the evaluation strategy is the influence of municipal characteristics on newborn health. A particular concern is the correlation of violence with poverty and with a weak local state, on the one hand, and between the latter two and newborn health, on the other, for instance through a lower state capacity to provide adequate health services<sup>34</sup> or via poor maternal nutrition (Amarante et al. 2016). Poor economic conditions can lead to conflict as they lower the opportunity cost for young unemployed men to take up arms, limit the capacity of governments to repress insurgencies, and exacerbate grievances between the state and its citizens, and across groups within a country (Collier and Hoeffler 2004; Fearon and Laitin 2003; Miguel,

> 28 In the sample, 80% of neonatal deaths occur by the first week of life.

> 29 When there is no information about pregnancy length, one could subtract 9 months (or 40 weeks) from the date of birth. However, this assigns all births the same gestation length, as if they all reached full term. This is especially problematic in the case of pre-term births, as these pregnancies would be assumed to start much earlier than they actually did, resulting in a misrepresentation of their exposure to violence during the early part of the pregnancy.

> 30 It is reported in months in the 2005 DHS, and in weeks in the 2010 and 2015 rounds, where months are multiplied by 4.3 to calculate the length in weeks.

> 31 Although because both the date of birth and the pregnancy length are reported by the mother in the survey, there can be some recall error leading to imprecision in its determination.

> 32 To account for different dates of birth within a month, the month of birth corresponds to the concurrent one if the birth was at the beginning of the month (i.e. before the 15th day); if the child was born after the 15th, it corresponds to the following month.

> 33 Supplementary analysis available upon request has an analysis based on the number of victims.

> 34 In Colombia, the provision of health services is a core government function devolved to municipalities.

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Satyanath, and Sergenti 2004; Stewart 2002). Sub-nationally, Dube and Vargas (2013) show how economic conditions in Colombian municipalities can trigger violence.

Comparing key municipal characteristics for places where there was ever an attack against those that never experienced one reveals a lack of significant differences in poverty (proxied by the share of unsatisfied basic needs), fiscal performance, and basic health services for children (proxied by the DPT vaccination rate), but municipalities that experience violence shocks are larger, are less rural and have fewer individuals receiving subsidized health insurance (which can suggest less eligible population or lower local resources for health). Because the endogeneity of municipal violence can be thought of as an omitted variable problem, I add these indicators as controls in the regression<sup>35</sup> Nonetheless, the variability of violence exposure through gestation within municipalities lessens the endogeneity problem as any potential municipal confounder would need to vary at the trimester level to bias the results. Following the strategy in Valente (2015), I also add a control for the cumulative attacks in each municipality three years (36 months) up to the beginning of the pregnancy ( p p p p p ); as this varies by municipality and date of conception, it should capture any time-trend in the occurrence of attacks; that is, any potential ii,mm,tt time-varying heterogeneity correlated with both changes in municipal violence over time, and pp birthweight. The main equation to estimate for the birthweight b p of child _i_ , conceived at time (month-year) _t_ , in municipality _m_ is as follows: ii,mm,tt bbhtt b p 1 2 3 1p p p p 2p p p p + 3p p p p 4p pcc p p p pp ymmy m (Eq.1) ii,mm,tt ii,mm,tt ii,mm,tt mm,tt mm,tt+3 mm,tt+6 bbhtt = αα+ ββ XX + ββ XX + ββ XX + δδ + δδ mm,tt+9 mm,tt−36 mmtth mm ii,mm,tt The terms δδ p p p + δδp ( _j=3,6,9_ pp) are the exposure to violence in each pregnancy trimester. I + γγ + γγ + γγ + εε estimate the terms separately, even though there is no full consensus on whether the impact of a mm,tt+jj stress shock is heterogeneous across the length of gestation (Persson and Rossin-Slater 2018) nor on the stage for which impacts should be visible.<sup>36</sup> The last trimester ends at birth, and because pregnancies are typically viable from the 24th week of gestation, or the end of the second trimester, the last one can be absent. The specification accounts for early births by interacting exposure to violence in the third trimester (p p p p ) with an indicator of the pregnancy not reaching such trimester ( ).<sup>37</sup> This allows to keep those pregnancies in the sample but without mm,tt+9 misrepresenting their exposure to violence, that is, without assuming that they had no exposure to ii,mm,tt an event in the last trimester, or that their exposure corresponded to the events that occurred in the mmppttp mm3 municipality in the months after their birth. The base coefficient ( 3) continues to be the parameter of interest for exposure to violence in this trimester.<sup>38</sup> δδ

> 35 The municipal controls vary by year or by survey round because of limited historical municipal data reported monthly, and sometimes even yearly. Yearly variables are linked with DHS on the year and month of birth: if the child was born after June, the value corresponds to that of the concurrent year; if the child was born before June, it corresponds to the previous year.

> 36 For instance, Mansour and Rees (2012) find effects for the third trimester, Valente (2015) for the second one, and Camacho (2008) and Quintana-Domeque and Ródenas-Serrano (2017) only for early-pregnancy.

> 37 In the sample, only 154 cases (0.52%).

> 38 Despite this, because gestational length is negatively associated with in utero shocks, there could be some bias introduced for correlated outcomes; for instance, mothers who are not exposed to stress can mechanically have higher birthweight because of the longer gestational length (Matsumoto 2018). In a robustness check, I try the alternative proposed by Matsumoto (2018) of using three full months for each pregnancy trimester, although the

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and are vectors with some standard child and mother/household characteristics known to affect newborn health: gender, an indicator of parity, the birth interval with respect to the cc pp ii,mm,tt ii,mm,tt XXprevious live birth, an indicator for a multiple birth (twins or more), for whether the birth was XX attended by a doctor or nurse, and for the day of birth (before/after the 15th of the month), the years of education of the mother, her age at birth, an indicator for whether she had any disability since birth or resulting from illness, the area of residence of the household (urban, rural or rural disperse), and a measure of multidimensional poverty.<sup>39</sup> are municipal characteristics previously defined; y y , m are time fixed-effects,<sup>40</sup> and mm are municipal fixed-effects. ii,mm,tt XX mmtth mm I exclude from the sample the children whose mothers migrated into municipalityγγ γγ γγ _m_ after _m_ after conception because they were exposed to different violence shocks. This could be solved by matching the violence data on the municipality of residence at the time of pregnancy, but it is not possible because DHS do not identify this place. Of the total sample of children with birthweight information, 15% of cases are excluded from the analysis for this reason,<sup>41</sup> but only a small proportion of mothers stated that they migrated as a result of violence: less than 6% of the pregnancies that occurred in a different municipality.<sup>42</sup> Instead, the most commonly stated reasons for migration, with about 44% of the responses each, were economic (‘looking for opportunities’ or ‘work') and family motives. I deal with migration arising from women moving out of municipalities exposed to violence as a robustness check.

# **V. Results**

# **A. Summary statistics**

Across the three DHS waves there are 37,500 observations of children born in the five years before each survey and whose mothers lived in the municipality of interview during since conception. Of those, 27,183 (72.49%) reported the baby’s weight at birth, 75% of which were from the mother’s recall, and 24.7% from a birth certificate or hospital record.<sup>43</sup> The average baby weighs 3.222 kg; girls are on average 110 gr lighter than boys _(_ Table 2 _),_ and their whole birthweight distribution is slightly to the left (Figure 3). 8.17% of babies are born weighing less than 2.5 kg, but because of the tendency to report birthweight in round multiples (heaping), it is preferred to include the threshold cases in a low birthweight indicator when using household survey data (Blanc and Wardlaw 2005). This adjustment brings the share of low birthweight babies in the sample to 11.79%. Less than 1% of babies die within the first 28 days of life in the sample of babies with birthweight data, and 1.1% in the full sample. In both cases, the boys’ rate of neonatal mortality is

> interpretation of this estimate would be slightly different, returning an intention to treat rather than an average treatment effect. Results do not significantly differ from the ones presented here and are available upon request. 39 Because DHS surveys have no information on household income or expenditure, I calculate the Multidimensional Poverty Index (MPI) following United Nations Development Programme guidelines for the international version of the index. Colombia has a local version (Angulo, Díaz, and Pardo 2013), but some of the indicators are not available in DHS. Here I use the household deprivation score, without capping it for households below the poverty threshold.

> 40 The specification also includes survey round fixed-effects.

> 41 The share is similar for the whole sample of children (including those without birthweight report) or when using only observations with the complete set of covariates.

> 42 There are also a few women who migrated within the municipality and these are included in the sample; 0.73% of them moved because of violence.

> 43 There are no statistically significant differences in birthweight, and only a very small one in the share of low birthweight when comparing the two reporting methods.

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higher than the girls’. Girls exposed to a violence shock during gestation are on average 900 gr lighter and more of them are under the low birthweight threshold that those who were not exposed. For boys, there is no average difference in the low birthweight shares, but the difference in birthweight is about 700 gr (Table 3). These differences are suggestive of the potential negative effect of being exposed to this type of violence during gestation, but do not control for differences across municipalities nor other confounders.

# [Table 2 and Table 3 here]

There is almost parity in the sex ratio. Because of the low fertility rate in Colombia (two births per woman in the latest DHS and below three births since the 1990s), a large percentage of births are the first for the women (42%). Just 2% of births are multiple, and almost all (97%) are attended by a doctor or nurse. Women are on average 26 years old when they give birth and have nine years of education (completed primary but not full secondary education). Among the mothers, 6% had a disability and, on average, they report to be in good health (a score of 2.9 out of 5). The average household multidimensional poverty score is 0.10.<sup>44</sup> Babies are on average born in municipalities with 38% of UBN and good municipal performance (3.2 out of 5). The provision of health services in these municipalities is good, with a high coverage of social health insurance (84%) and of DPT vaccination (85%).

# **B. Violence and newborn health**

Tables 4 to 6 show the relationship between the different outcomes — birthweight, low birthweight, neonatal mortality — and exposure to a violence shock in the first (δ1), second (δ2) and third (δ3) gestation trimesters. In these results the end of the pregnancy is the actual date of birth.<sup>45</sup> The coefficient for the first trimester in column 1 indicates an average decline in birthweight of 41 gr for the babies of mothers exposed to an attack, but this is only statistically significant close to the 10% confidence level. Exposure in the following trimesters does not appear to affect birthweight. The education of the mother is a strongly significant explanatory variable for weight at birth, and to investigate whether the negative effect of the shock varies with this maternal characteristic, I interact the two (column 2). The second and third trimester coefficients and their interactions remain statistically insignificant. In contrast, the base coefficient for the first trimester becomes statistically significant at the 1% level and indicates that newborns of non-educated mothers weight 159 gr less (about a quarter of a standard deviation) if exposed to a violent attack in the municipality of residence; the interaction sign indicates a declining gradient in this effect, with each additional year of education of the mother reducing the impact by 12 gr. I also interact the coefficient of violence exposure with the multidimensional poverty measure (column 3) or with the wealth index (column 4), but while both variables are important determinants of birthweight on their own, neither appears to mitigate the effect of the violence shock. Although these are crude measures of family resources, this suggests that the protecting effect of the education of the mother is unlikely to be a proxy for lower credit constraints.

> 44 The index ranges from zero to one.

> 45 Since a shock in utero can precipitate birth, I present an alternative specification using the expected date of birth at full term as reference, but because qualitatively these results are similar, the latter will only be discussed when there are important aspects to highlight. These and other various other robustness checks are available upon request.

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In column 5 I check for gender differences. The insignificant coefficient for the male interaction indicates no gap in the average effect, but because of the importance of considering the interaction with the maternal education, columns 6 and 7 include this in separate girls/boys sub-samples. The negative impact of violence exposure in the first trimester is only statistically significant for the boys, in whom it is close to twice as large as the full sample effect; the mitigating effect of the mother’s education is 29 gr per additional year of education. Figure 4 more clearly shows these results by plotting the estimated marginal effect for the children of women without any schooling, 5, 9, 11 and 16 years of education. For girls, the effect is small, mostly statistically insignificant and without much variation along the maternal education. For boys, there is a large negative effect for the least educated mothers, which falls quickly and becomes statistically zero for mothers with completed primary education.<sup>46</sup> To consider the effect for babies who are more at risk of malnourishment and illness I look at the effect on a critical point in the birthweight distribution (Table 5). Violence exposure in the first trimester is positively associated with the likelihood of low birthweight (≤2.5 kg)<sup>47</sup> but only statistically significant when considering the heterogeneity with respect to the mothers’ education. There are gender differences in the average effect, with that of boys being slightly higher. Heterogeneous effects are also driven by the boys’ sub-sample and the lower end of the maternal education distribution. The likelihood of being born with low birthweight for a boy of a loweducated mother exposed to violence in early-pregnancy is 12.8 percentage points higher, falling by 1.3 percentage points for each additional year of education. For girls, there is no effect of a violence shock in the first trimester of gestation, but for the last one there is a 13.6 percentage points increase in the likelihood of being born with low birthweight if their mothers have no education; this effect is also mitigated by 1.7 percentage points for each additional year of education, although this last effect is not statistically significant in the alternative specification with the expected DoB.

Exposure to violence in early-pregnancy seems to decrease the risk of neonatal mortality<sup>48</sup> for children of the lowest educated mothers and only for girls. The effect is small but could be a sign of a dominating selection effect. This is, however, unlikely because no such health improvement was observed for birthweight, and the fetal mortality results neither support the hypothesis. A more likely explanation is that the mechanisms making girls more resilient to early-pregnancy shocks carry over into early-life. The interaction of the effect with maternal education is not statistically significant but Figure 4 shows a small gradient.

The negative effect of exposure to violence on neonatal mortality is seen in the second trimester with the interaction with maternal education (column 2). In the gender interaction the average effect is smaller and close to zero, for boys; the gender split shows that the negative effect (an increase in early-life mortality) of a second trimester shock is driven by the girls’ sub-sample and the lower end of the maternal education distribution (Figure 5). A shock in the last trimester has a similar effect, although not statistically significant.

[Table 5 and Table 6 here]

> 46 It is even positive for the highest-educated mothers.

> 47 Results for a stricter definition of birthweight (<2.5 kg) are available upon request.

> 48 Children born less than 28 days before the survey are excluded.

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# **C. Mortality, fertility and migration**

The full effect of violence can be underestimated if the shock increases fetal deaths (survival selection). Using the DHS’s pregnancy calendar, it is possible to distinguish between live births and terminations<sup>49</sup> and analyze the effect on this outcome. Despite known difficulties in capturing information about fetal mortality, we do not expect this problem to be more pronounced in Colombia than elsewhere, especially poorer countries where more births and deaths occur outside of the health system. Only pregnancies within five years from the survey are used, a standard procedure used to alleviate recall error. The models are estimated as in Equation 1 but without controlling for gender, multiple birth and skilled delivery, as this information is not available for non-live births.<sup>50</sup> Because terminations tend to happen early in the pregnancy,<sup>51</sup> I interact the indicators of exposure to violence in the second and third trimesters with a dummy for whether the pregnancy reached those trimesters, and check the results with the alternative method of using the expected full-length trimesters. Because the number of cases per woman is much larger than for live births, I can further estimate a mother fixed-effects model.

There are 39,500 thousand pregnancies from non-migrant women, of which 18% do not end in a live birth. Compared to the live births sample, exposure to violence here is lower, with 2.5% of pregnancies exposed during gestation. The share of live births among exposed pregnancies is not significantly lower compared with those that were not exposed (91.3% vs 81.9%). The regression results, where this relationship between violence and the outcome of the pregnancy (terminated or live birth) is examined are in Table 7 (columns 1-5). Overall, there is not a significant effect of a shock in the first trimester on the likelihood of a terminated pregnancy, neither in the base specifications (columns 1 and 2), the mother fixed-effects (column 3), nor the alternative trimester determination method (columns 4 and 5). Exposure to violence later in the pregnancy, especially in the second trimester, may reduce the likelihood of a termination, but this result is statistically weak and not always significant.

Since only boys’ birthweights were negatively affected by violence shocks in early-pregnancy, it is possible that fetal mortality is also gender selective. This cannot be directly verified because the gender of the fetus is not specified in the data, but I use instead the gender ratio at birth in the sample of live births as a signal for changes in gender specific terminations (Table 7 columns 6 and 7 ) (as in Sanders and Stoecker (2015) and Valente (2015)). Although the 1 coefficient is negative, it is not significant enough to support the hypothesis of a boy-specific mortality rise. δδ

# [Table 7 here]

A second source of selection bias can occur if violence triggers fertility changes. For example, if more educated people reacted differently to the shock, the sample of births could have worse health because of this compositional change on who becomes a parent and not because of exposure to

> 49 A full pregnancy history distinguishing miscarriage from stillbirths, abortions and ectopic pregnancies is only available in the latest round of the survey.

> 50 Since the day of the pregnancy end is not known in the calendar data, the date of conception is not adjusted for the time of the month and thus can be subject to greater measurement error than the date of conception of the live births sample.

> 51 In the sample, terminated pregnancies last 2.4 months on average, 91.3% of pregnancies that reach the seventh month are live births, and 99.6% at the ninth month.

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violence in utero. It is, however, unlikely that parents can predict and alter their fertility behavior in response to month-to-month variations in violence (Valente 2015), especially for a shock as unpredictable as violent attacks against civilians. Moreover, the time fixed-effects in the regressions already control for possible trends and seasonal variation in fertility, and the controls for mother characteristics would also capture some of this selection. Still, I assess the characteristics of the mothers exposed to violence before and during pregnancy to check for any compositional effect based on observables.

T-test comparisons show that mothers exposed to violence while pregnant or in the previous nine months are not older, more likely to have a disability, nor come from poorer households on average.<sup>52</sup> They are more educated, particularly less likely to have less than primary education.<sup>53</sup> Thus, if there was some bias, it would work in the same direction of the expected effect, making the estimates presented here lower bounds of the true effect. Still, when exploring the evidence in a regression framework that controls for within-municipality variation<sup>54</sup> (by estimating equation 1 using mother characteristics as dependent variables) (Table 8), this difference disappears, and there is no other indication of a composition effect<sup>55</sup> on the mothers resulting from exposure to violence before or during pregnancy.<sup>56</sup> Women are also asked whether the pregnancy was intended (wanted to get pregnant when they did), inconvenient (wanted to get pregnant later) or unintended (did not want any more children). The t-statistics indicate that pregnancies exposed to violence in utero were not less likely to be desired, but exposure in the months before conception is associated with more inconvenient and unintended pregnancies. In the regression framework and separating by the gender of the child, we see that this change in fertility preferences is driven by an increase in the desirability (vs. inconvenient or unintended) of male pregnancies for women exposed to a violence event six to nine months before conception.

# [Table 8 here]

Finally, there is the possible selection issue arising from migration. Inwards migration is discounted by the exclusion of mothers who arrived in the municipality after becoming pregnant. More problematic would be if attacks triggered mass migration as the observed women would be a small proportion of the population before the attack. If those staying were systematically different from the leavers, the estimates could be biased.<sup>57</sup> Mean comparisons reveal that newcomer migrant mothers are not significantly different in education, disability prevalence, household multidimensional poverty or wealth, but this only provides a rough indication of the (lack of) bias.

> 52 Results available upon request.

> 53 Perhaps because attacks against civilians are more prevalent in larger and more urban municipalities where levels of education are higher.

> 54 Another alternative is to use the variation across babies from the same mother born at different times (mother fixed-effects). However, the sample size would be too small for any reasonable estimation, given the low fertility rate in Colombia and number of live births per woman in our data. Moreover, the external validity of mother fixed-effects models can be much lower.

> 55 Except a reduction in the likelihood of the woman having a disability when exposed in the trimester immediately before conception.

> 56 A further robustness check that addresses potential fertility changes excludes from the control group (those not exposed to the shock in utero) those births conceived in a municipality with an attack within 3 years before conception. This leads to virtually similar conclusions about the effect on birthweight.

> 57 Migrants could be more heavily affected by violence if they are direct victims, suffering from greater violence-induced stress, but they can also be more educated, healthier or wealthier to have the capacity and resources to move.

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To have a better sense of the potential direction of this bias, in the absence of information from women who have left the municipalities surveyed, I exclude from the analysis cases from 66 municipalities with a high displacement (IDP) expulsion rate in any given year. These municipalities have a per capita IDP expulsion rate above a standard deviation from the national average in the period. It is notable that only two of the excluded ones (Tumaco and Puerto Rico) had an attack against civilians in the period, which reinforces the idea that these events are shocks lowly correlated with persistent levels of violence. The results (Table 9) show that the sign, magnitude and statistical significance of the first trimester coefficient remain similar, suggesting that results are not driven by births in high displacement areas.

# [Table 9 here]

# **D. Behaviors during pregnancy**

As a final exercise, I examine whether key behaviors during pregnancy are affected by violence. Following Currie, Mueller-Smith and Rossin-Slater’s (2018) method, I construct an index comprised of the following indicators captured from the responses given by pregnant women in DHS: smoking, drinking alcohol, attending the minimum recommended prenatal care visits (eight visits per WHO guidelines), and receiving a tetanus vaccine. The index is an equally weighted average of the standardized behaviors.<sup>58</sup> To standardize, I subtract the mean and divide by the standard deviation of the behavior in non-exposed pregnancies.<sup>59</sup> The discussion focuses on the results including the interaction with maternal education (Table 10, columns 2 to 5), since this was found to be a relevant heterogeneity in the main analysis and it is an important known source of differences in parental investments in child health (Rosenzweig and Schultz 1982).

Exposure to violence in the second trimester is associated with an increase in potentially adverse maternal behaviors during pregnancy. The negative coefficient of the maternal education variable, and the interaction with exposure to violence indicate that not only more educated mothers incur less on these behaviors on average but also when exposed violence during pregnancy. When splitting the cases by gender of the baby, we observe that the effect of violence exposure on these behaviors is only present for girls. There is an increase in adverse behaviors for mothers of girls exposed to a violent attack against civilians in the first and especially the second trimester, although also a smaller decrease if they are exposed in the last trimester. The adverse behaviors’ results are driven by the increase in the likelihood of drinking the decrease in antenatal care and the likelihood of receiving a tetanus vaccination for women exposed to violence in the first and second trimesters, particularly for lower-educated women. The case of tetanus vaccination is interesting because it does not affect birthweight through any direct improvement of the prenatal environment (the vaccine is used to prevent infection during delivery), but its positive effect is indirect, through the complementarity with other parental prenatal investments (Mwabu 2008).<sup>60</sup> In sum, the effect on this indicator could be pointing to the desire of parents to make other unobserved investments in the child’s health.

> 58 Positive behaviors (prenatal care visits and tetanus vaccinations) are inverted to indicate a negative behavior.

> 59 Results for the individual variables are available upon request.

> 60 The vaccine increases the survival chance after birth and hence, parents are motivated to invest in this input only if other complementary inputs are available (Mwabu 2008).

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# [Table 10 here]

Even though the survey data used in this section have some noted limitations, primarily that prevalence of the behaviors before conception and the timing during the pregnancy are not known,<sup>61</sup> the results presented are suggestive of changes in key maternal behaviors important for newborn outcomes, and overall, in a negative direction for mothers who give birth to baby girls. Some potential explanations behind these patterns of behavioral change emerge from the literature. Parents may respond differently to the shock depending on the gender of the baby, for example, if they knew that male fetuses are more vulnerable and need more protection from shocks (Bharadwaj and Lakdawala 2013). It is known that intra-household allocations are not even, with parents investing more in the human capital of their preferred children (e.g. Do and Phung 2010). Hence, it would be possible that, as investments in the baby’s health, the differential maternal behaviors responses are driven by biased gender preferences held by parents. This would be hard to corroborate, not least because, to my knowledge, there is no evidence of boy preference in Colombia that could easily substantiate the claim.<sup>62</sup> Although the surveys do not have enough information to say whether these changes occurred before or after knowing the gender of the baby, it is likely, as most of the changes were associated with exposure to violence in the later stages of pregnancy, when the gender of the fetus is likely be known.<sup>63</sup>

# **VI. Conclusion**

This study set out to analyze one indirect effect of war violence: the one caused by exposure of pregnant women on their newborns’ health. Violent attacks against civilians were used to capture such exposure, which emphasizes the experience of violence in the community where people live, because the distress, fear and anxiety do not arise exclusively through individual victimization. The identification of the effect relied in the variation of exposure to violence by municipality of residence of the mother while pregnant, and the gestation stage when violence occurs.

The main finding was that mothers exposed to violence during early-pregnancy gave birth to babies who weighed less and had higher odds of being underweight. This effect was visible for the sub-sample of baby boys, but not of baby girls, and when focusing on newborns whose mothers were at the lower end of the maternal education distribution. This finding has implications for the intergenerational transmission of disadvantage, since it indicates that the children of disadvantaged women exposed to in utero shocks are born with poorer health. Pregnancy is a key developmental stage, and the poorer health at birth of these children can result in lifelong disparities in health and in other areas of well-being. The benefits of early-life interventions are particularly cost-effective in the long-run (Heckman 2000); a priority for policies seeking to reduce disparities in outcomes would be to protect vulnerable expecting mothers from shocks or to provide avenues, beyond the easing of financial constraints, to alleviate their negative effects. The outcomes analyzed in this study referred to specific aspects of newborn health, namely growth and early-life mortality, but

> 61 For instance, we do not know if the women smoked during the first, second or third trimester nor whether she also did it before conception. Also, because these survey questions are only asked to women (of reproductive age) who had a live birth within five years of the survey, it is impossible to assess them for pregnancies where the fetus did not survive to birth.

> 62 If anything, according to mothers’ statements in DHS surveys, the bias would slightly favour girls. For instance, the reported share of unintended pregnancies is 23.02% when the baby is a girl, and 23.4% when it is a boy.

> 63 This is around the 18th-20th week (second trimester), and prenatal ultrasounds are common and widely accessed in Colombia.

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this does not preclude other potential impacts. For instance, the body’s reaction to stress also involves parts of the brain that control mood, fear and motivation, opening the potential to analyze outcomes beyond physical health. Analyzing these outcomes is not possible with DHS data but it could feed future work.

The main results were unlikely to be driven by a change in the composition of mothers, either because of migration or fertility changes. They were also robust to alternative specifications that tested for the possibility of being driven by concurrent shocks, albeit with the significance of the effect faded when focusing only on singletons or on babies born within healthy birthweight ranges. Given variation in the size of the estimate across robustness specifications, the known problems with the report of birthweight in household surveys, and the low sample sizes at higher degrees of disaggregation (for instance, the group of low educated mothers), it may be relevant for future work to validate some of the headline findings with administrative data from birth records, which cover the universe of births.

Another important result was the absence of change in fetal mortality or in the gender ratio at birth associated with a violence shock. These results complement those from earlier studies in poorer countries and would support the hypothesis that the balance between scarring and selection effects differs across countries, and particularly, that in a middle-income developing country such as Colombia the scarring of health caused by a violence shock is stronger.

A gender split in the results would be in line with the medical literature where it is well established that male fetuses are more vulnerable to in utero shocks. However, unlike previous related work where the effects were mostly concentrated on boys, here I also found some impact of in utero violence exposure for girls.<sup>64</sup> It has been hypothesized that the mechanism for the intergenerational transmission of exposure to violence is the hormonal imbalance resulting from the maternal experience of stress. The effect for girls was not visible when exposure to violence was in the first trimester of gestation but only when it occurred in late stages, which is at odds with this expectation of the biological channel being more harmful in early fetal development.

I used information about maternal behaviors during pregnancy as an attempt to disentangle other possible channels. The nature of the data warrants care in the interpretation of these results, but the exploratory analysis presented here is worth continuing in future work. I found that exposure to violence led to changes in some maternal pregnancy behaviors. There was a reduction in the chance of attending antenatal care visits, receiving a tetanus vaccination and an increase in the likelihood of drinking alcohol, and these changes were significant for women pregnant with girls, and especially strong in the second trimester of gestation. The hypothesis is that the increase in these behaviors creates a harsher intrauterine environment for girls, leaving them more vulnerable to environmental stressors and thus to scarring during late gestation. In this period, stress hormones should be less harmful for fetuses, leaving more room for other intrauterine environmental factors to affect the pregnancy outcomes.

Although we cannot be conclusive with respect to whether these behavioral results are a reflection of a parental preference for boys over girls, the analysis complements the literature on skewed

> 64 The generalizability of these results for girls is subject to certain limitations. Importantly, the effect was only evident when considering the likelihood of being born with low birthweight, which is a measure suffering from reporting issues, especially when the data come from the mother’s recall.

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parental investments beginning in the womb (Bharadwaj and Lakdawala 2013), even for a country such as Colombia, where the evidence on biased gender preferences is scarce. Investigating why parents react to shocks differently according to the gender of the child and whether exposure to a conflict environment changes parental preferences for their offspring are emerging research agendas worth continuing. The skewness of parental investments along gender lines could accentuate in times of conflict and son preference can intensify in periods of hardship where such bias was already prevalent in normal times (Das Gupta and Shuzhuo 1999). For instance, Kraehnert et al (2017) and Verwimp and Van Bavel in Rwanda show that victims of conflict increase fertility as a way to compensate for the loss of time and children<sup>65</sup> associated with the war period. Since most of the war deaths are male, an increased desirability for male offspring could result as mothers preventively wishing to substitute for their higher expected mortality (Schultz 1969). This could be related to a desire to continue the family line, especially in patrilineal societies,<sup>66</sup> or from expected higher returns or lower perceived riskiness of male human capital investments, if parents use transfers to children as a form of old-age income insurance (Quisumbing 1994; for example, as in Rosenzweig 1988; Schultz 1997).<sup>67</sup> As it was noted earlier, even in Colombia, where a gender preference for boys is not well documented, the value of boys relative to girls seems to rise for mothers exposed to violence around the time of conception. Such increased valuation of boys relative to girls in populations exposed to conflict could be behind the changes in behaviors documented in this paper and are consistent with increased investments in male offsprings’ human capital for conflicts elsewhere (e.g. in Armenia (Mavisakalyan and Minasyan 2018) and in Tajikistan (Shemyakina 2011)).<sup>68</sup> The findings have implications for the understanding of the intergenerational transmission of disadvantage. Children of less-educated women exposed to in utero shocks are born with poorer health, which can further result in disparities in health and in other areas of well-being throughout their lives. Because remediation interventions at early stages of life can be particularly costeffective in the long-run (Heckman 2000), and because policies that reduce the incidence of low birthweight have multiple benefits (Alderman and Behrman 2006), a priority for policies seeking to reduce disparities in outcomes would be to protect vulnerable expecting mothers from shocks or to provide avenues to alleviate their negative effects. Special attention would need to placed on intrahousehold disparities in parental inputs to newborn and child human capital formation, especially along gender lines, as it seemed possible from the results here that expecting parents compensate the negative effects of shocks for boys but not for girls. Further investigating why and when parents react to shocks differently according to the gender of the child is an important research agenda to continue exploring.

> 65 Resulting from higher child mortality rather than direct deaths.

> 66 Verwimp and Van Bavel (2005) also note that the diminished survival of refugees’ daughters but not of their sons, could suggest an increase in parental investments in boys’ health as a way to shield them from the harmful effects of conflict and ensuring the passing on of land rights, which in Rwanda follow the male line.

> 67 Another possibility not formalized in the literature but which could play a role is the increased desire for males in the family as perceived providers of security in a conflict environment.

> 68 Although surprisingly, preliminary work in Colombia (Camacho and Gerardino 2018) shows the opposite: a decrease in overall actual and desired fertility, and a relative decrease in the desired male fertility for populations exposed to homicide violence. The discrepancy with respect to the results here may be related to the choice of measure, as that used by these authors is based on the _stated_ desire for boys/girls (women are asked about their fertility desires, if they could start again, or to recall their feelings towards each pregnancy), and that here is based on reported behaviors, which may not align. Norling (2018), for instance, shows that parents underreport their preferences for sons/daughters compared to what their actual fertility behavior indicates.

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