TY - JOUR AU - Almond, Douglas AU - Currie, Janet DA - 2011 PY - 2011 DO - 10.1257/jep.25.3.153 IS - 3 SN - 08953309 T2 - Journal of Economic Perspectives TI - Killing me softly: The fetal origins hypothesis VL - 25 ID - ITEM-1 ER - TY - JOUR AU - Wadhwa, Pathik D. AU - Sandman, Curt A. AU - Porto, Manuel AU - Dunkel-Schetter, Christine AU - Garite, Thomas J. DA - 1993 PY - 1993 DO - 10.1016/0002-9378(93)90016-C IS - 4 SN - 00029378 T2 - American Journal of Obstetrics and Gynecology TI - The association between prenatal stress and infant birth weight and gestational age at birth: A prospective investigation VL - 169 ID - ITEM-1 ER - TY - JOUR AU - MacKinnon, James G. AU - Webb, Matthew D. DA - 2020 PY - 2020 AB - Inference using difference-in-differences with clustered data requires care. Previous research has shown that, when there are few treated clusters, t-tests based on cluster-robust variance estimators (CRVEs) severely overreject, and different variants of the wild cluster bootstrap can either overreject or underreject dramatically. We study two randomization inference (RI) procedures. A procedure based on estimated coefficients may be unreliable when clusters are heterogeneous. A procedure based on t-statistics typically performs better (although by no means perfectly) under the null, but at the cost of some power loss. An empirical example demonstrates that RI procedures can yield inferences that differ dramatically from those of other methods. DO - 10.1016/j.jeconom.2020.04.024 IS - 2 SN - 18726895 T2 - Journal of Econometrics TI - Randomization inference for difference-in-differences with few treated clusters VL - 218 ID - ITEM-1 ER - TY - JOUR AU - Mackinnon, James G. AU - Webb, Matthew D. DA - 2019 PY - 2019 AB - When there are few treated clusters in a pure treatment or difference-in-differences setting, t tests based on a cluster-robust variance estimator can severely over-reject. Although procedures based on the wild cluster bootstrap often work well when the number of treated clusters is not too small, they can either over-reject or under-reject seriously when it is. In a previous paper, we showed that procedures based on randomization inference (RI) can work well in such cases. However, RI can be impractical when the number of possible randomizations is small. We propose a bootstrap-based alternative to RI, which mitigates the discrete nature of RI p values in the few-clusters case. We also compare it to two other procedures. None of them works perfectly when the number of clusters is very small, but they can work surprisingly well. DO - 10.1108/S0731-905320190000039003 SN - 07319053 T2 - Advances in Econometrics TI - Wild bootstrap randomization inference for few treated clusters VL - 39 ID - ITEM-2 ER - TY - JOUR AU - Roodman, David AU - MacKinnon, James G. AU - Nielsen, Morten Ørregaard AU - Webb, Matthew D. DA - 2019 PY - 2019 AB - The wild bootstrap was originally developed for regression models with heteroskedasticity of unknown form. Over the past 30 years, it has been extended to models estimated by instrumental variables and maximum likelihood and to ones where the error terms are (perhaps multiway) clustered. Like bootstrap methods in general, the wild bootstrap is especially useful when conventional inference methods are unreliable because large-sample assumptions do not hold. For example, there may be few clusters, few treated clusters, or weak instruments. The package boottest can perform a wide variety of wild bootstrap tests, often at remarkable speed. It can also invert these tests to construct confidence sets. As a postestimation command, boottest works after linear estimation commands, including regress, cnsreg, ivregress, ivreg2, areg, and reghdfe, as well as many estimation commands based on maximum likelihood. Although it is designed to perform the wild cluster bootstrap, boottest can also perform the ordinary (nonclustered) version. Wrappers offer classical Wald, score/Lagrange multiplier, and Anderson-Rubin tests, optionally with (multiway) clustering. We review the main ideas of the wild cluster bootstrap, offer tips for use, explain why it is particularly amenable to computational optimization, state the syntax of boottest, artest, scoretest, and waldtest, and present several empirical examples. DO - 10.1177/1536867X19830877 IS - 1 SN - 15368734 T2 - Stata Journal TI - Fast and wild: Bootstrap inference in Stata using boottest VL - 19 ID - ITEM-1 ER - TY - CONF AU - Camacho, Adriana DA - 2008 PY - 2008 DO - 10.1257/aer.98.2.511 IS - 2 SN - 00028282 T2 - American Economic Review TI - Stress and birth weight: Evidence from terrorist attacks VL - 98 C2 - 2008 C3 - American Economic Review ID - ITEM-1 ER - TY - JOUR AU - Dube, Oeindrila AU - Vargas, Juan F. DA - 2013 PY - 2013 AB - How do income shocks affect armed conflict? Theory suggests two opposite effects. If labour is used to appropriate resources violently, higher wages may lower conflict by reducing labour supplied to appropriation. This is the opportunity cost effect. Alternatively, a rise in contestable income may increase violence by raising gains from appropriation. This is the rapacity effect. Our article exploits exogenous price shocks in international commodity markets and a rich dataset on civil war in Colombia to assess how different income shocks affect conflict.We examine changes in the price of agricultural goods (which are labour intensive) as well as natural resources (which are not).We focus on Colombia's two largest exports, coffee and oil. We find that a sharp fall in coffee prices during the 1990s lowered wages and increased violence differentially in municipalities cultivating more coffee. This is consistent with the coffee shock inducing an opportunity cost effect. In contrast, a rise in oil prices increased both municipal revenue and violence differentially in the oil region. This is consistent with the oil shock inducing a rapacity effect.We also show that this pattern holds in six other agricultural and natural resource sectors, providing evidence that price shocks affect conflict in different directions depending on the type of the commodity. © The Author 2013. Published by Oxford University Press on behalf of The Review of Economic Studies Limited. DO - 10.1093/restud/rdt009 IS - 4 SN - 00346527 T2 - Review of Economic Studies TI - Commodity price shocks and civil conflict: Evidence from Colombia VL - 80 ID - ITEM-2 ER - TY - JOUR AU - Camacho, Adriana AU - Rodriguez, Catherine DA - 2013 PY - 2013 AB - This article uses two unique panel data sets to study the causal effect that armed conflict has over firm exit in Colombia. Using a fixed-effect estimation methodology at the plant level and controlling for the possible endogeneity of armed conflict through the use of instrumental variables, we find that a one-standard deviation (SD) increase in the number of guerrilla and paramilitary attacks in a municipality increases the probability of plant exit in 5.5 percentage points or .28 SD. This effect is stronger for younger manufacturing plants, with a smaller number of workers and low levels of capital. © The Author(s) 2012. DO - 10.1177/0022002712464848 IS - 1 SN - 00220027 T2 - Journal of Conflict Resolution TI - Firm Exit and Armed Conflict in Colombia VL - 57 ID - ITEM-3 ER - TY - JOUR AU - Angrist, Joshua D. AU - Kugler, Adriana D. DA - 2008 PY - 2008 AB - We study the consequences of an exogenous upsurge in coca prices and cultivation in Colombia, where most coca leaf is now harvested. This shift generated only modest economic gains in rural areas, primarily in the form of increased self-employment earnings and increased labor supply by teenage boys. The rural areas that saw accelerated coca production subsequently became considerably more violent, while urban areas were affected little. These findings are consistent with the view that the Colombian civil conflict is fueled by the financial opportunities that coca provides and that rent-seeking by combatants limits the economic gains from coca. © 2008 by the President and Fellows of Harvard College and the Massachuselts. DO - 10.1162/rest.90.2.191 IS - 2 SN - 00346535 T2 - Review of Economics and Statistics TI - Rural windfall or a new resource curse? coca, income, and civil conflict in Colombia VL - 90 ID - ITEM-4 ER - TY - JOUR AU - Vargas, Juan F. DA - 2012 PY - 2012 AB - Focusing on the Colombian armed conflict, this paper develops for the first time a within-country analysis of violence duration. It examines a wide range of factors potentially associated with violence duration at the municipal level for the period 1988-2004, including geographic factors, economic and social variables, institutional characteristics, victimization variables and government intervention. It individuates the most robust correlates of the persistence of localized conflict, both across specifications and using different econometric models of duration analysis. Results suggest that violence in Colombia is more persistent in places where illegal rents are available. Better quality institutions and a more active military are in turn associated with shorter conflict episodes. © 2012 Copyright Taylor and Francis Group, LLC. DO - 10.1080/10242694.2011.597234 IS - 2 SN - 10242694 T2 - Defence and Peace Economics TI - The persistent Colombian conflict: Subnational analysis of the duration of violence VL - 23 ID - ITEM-5 ER - TY - JOUR AU - Duque, Valentina DA - 2017 PY - 2017 AB - This paper investigates how the exposure to violent conflicts in utero and in early and late childhood affect human capital formation. I focus on a wide range of child development outcomes, including novel cognitive and non-cognitive indicators. Using monthly and municipality-level variation in the timing and severity of massacres in Colombia from 1999 to 2007, I show that children exposed to terrorist attacks in utero and in childhood achieve lower height-for-age (0.09 SD) and cognitive outcomes (PPVT falls by 0.18SD and math reasoning and general knowledge fall by 0.16SD), and that these results are robust to controlling for mother fixed-effects. The timing of these exposures matters and differs by type of skill. In terms of parental investments, I find some evidence that parents reinforce the negative effects of violence by increasing their frequency of physical aggression. DO - 10.1016/j.ssmph.2016.09.012 SN - 23528273 T2 - SSM - Population Health TI - Early-life conditions and child development: Evidence from a violent conflict VL - 3 ID - ITEM-1 ER - TY - JOUR AU - Mansour, Hani AU - Rees, Daniel I. DA - 2012 PY - 2012 AB - No previous study has estimated the effect of intrauterine exposure to armed conflict on pregnancy outcomes. Drawing on data from the 2004 Palestinian Demographic and Health Survey, which was conducted approximately 4. years after the start of the al-Aqsa Intifada, we find that an additional conflict-related fatality 9-6. months before birth is associated with a modest increase in the probability of having a child who weighed less than 2500. g. There is also evidence, albeit less consistent, of a positive relationship between fatalities in late pregnancy and low birth weight. © 2011 Elsevier B.V. DO - 10.1016/j.jdeveco.2011.12.005 IS - 1 SN - 03043878 T2 - Journal of Development Economics TI - Armed conflict and birth weight: Evidence from the al-Aqsa Intifada VL - 99 ID - ITEM-1 ER - TY - JOUR AU - Foureaux Koppensteiner, Martin AU - Manacorda, Marco DA - 2016 PY - 2016 AB - This paper uses microdata from Brazilian vital statistics on births and deaths between 2000 and 2010 to estimate the impact of in-utero exposure to local violence - measured by homicide rates - on birth outcomes. The estimates show that exposure to violence during the first trimester of pregnancy leads to a small but precisely estimated increase in the risk of low birthweight and prematurity. Effects are found both in small municipalities, where homicides are rare, and in large municipalities, where violence is endemic, and are particularly pronounced among children of poorly educated mothers, implying that violence compounds the disadvantage that these children already suffer as a result of their households' lower socioeconomic status. DO - 10.1016/j.jdeveco.2015.11.003 SN - 03043878 T2 - Journal of Development Economics TI - Violence and birth outcomes: Evidence from homicides in Brazil VL - 119 ID - ITEM-1 ER - TY - JOUR AU - Firpo, Sergio AU - Fortin, Nicole M AU - Lemieux, Thomas DA - 2009 PY - 2009 IS - 3 SN - 0012-9682 SP - 953-973 T2 - Econometrica TI - Unconditional quantile regressions VL - 77 ID - ITEM-1 ER - TY - JOUR AU - Rios-Avila, Fernando DA - 2020 PY - 2020 AB - Recentered influence functions (RIFs) are statistical tools popularized by Firpo, Fortin, and Lemieux (2009, Econometrica 77: 953–973) for analyzing unconditional partial effects on quantiles in a regression analysis framework (unconditional quantile regressions). The flexibility and simplicity of these tools have opened the possibility to extend the analysis to other distributional statistics using linear regressions or decomposition approaches. In this article, I introduce one function and two commands to facilitate the use of RIFs in the analysis of outcome distributions: rifvar() is an egen extension used to create RIFs for a large set of distributional statistics, rifhdreg facilitates the estimation of RIF regressions enabling the use of high-dimensional fixed effects, and oaxaca_rif implements Oaxaca–Blinder decomposition analysis (RIF decompositions). DO - 10.1177/1536867X20909690 IS - 1 SN - 15368734 T2 - Stata Journal TI - Recentered influence functions (RIFs) in Stata: RIF regression and RIF decomposition VL - 20 ID - ITEM-1 ER - TY - JOUR AU - Quintana-Domeque, Climent AU - Ródenas-Serrano, Pedro DA - 2017 PY - 2017 AB - We study the effects of in utero exposure to terrorism in Spain on birth outcomes, focusing on terrorism perpetrated by ETA during the period 1980–2003. We find that in utero exposure to terrorism early in pregnancy, as measured by the number of bomb casualties in the mother's province of residence in the first trimester of pregnancy, has detrimental effects on birth outcomes: in terms of average birth weight (lower), prevalence of low birth weight (higher) and fraction of “normal” babies (lower). While our findings are robust to a host of potential threats to validity, they seem to be driven by exposure to a relatively large number of bomb casualties. Focusing on the deadliest ETA terrorist attack, the Hipercor bombing of 1987 in Barcelona, we find substantial effects on birth outcomes. We then attempt to assess the mechanisms at stake by presenting evidence suggesting that exposure to bomb casualties decreases self-reported health and increases smoking among women, but not among men. While exposure to terrorism during conception does not affect total fertility, there seems to be a compositional change: during bombing periods, those women who conceive are more likely to be married, and married women tend to have better birth outcomes, on average. In addition, we find that exposure to bomb casualties increases fetal deaths. Thus, we interpret our estimated negative effects on health at birth as providing lower bounds to the true effects of in utero exposure to terrorism. DO - 10.1016/j.jhealeco.2017.08.006 SN - 18791646 T2 - Journal of Health Economics TI - The hidden costs of terrorism: The effects on health at birth VL - 56 ID - ITEM-1 ER - TY - JOUR AU - Torche, Florencia DA - 2011 PY - 2011 AB - A growing body of research highlights that in utero conditions are consequential for individual outcomes throughout the life cycle, but research assessing causal processes is scarce. This article examines the effect of one such condition-prenatal maternal stress-on birth weight, an early outcome shown to affect cognitive, educational, and socioeconomic attainment later in life. Exploiting a major earthquake as a source of acute stress and using a difference-in-difference methodology, I find that maternal exposure to stress results in a significant decline in birth weight and an increase in the proportion of low birth weight. This effect is focused on the first trimester of gestation, and it is mediated by reduced gestational age rather than by factors affecting the intrauterine growth of term infants. The findings highlight the relevance of understanding the early emergence of unequal outcomes and of investing in maternal well-being since the onset of pregnancy. © 2011 Population Association of America. DO - 10.1007/s13524-011-0054-z IS - 4 SN - 15337790 T2 - Demography TI - The Effect of Maternal Stress on Birth Outcomes: Exploiting a Natural Experiment VL - 48 ID - ITEM-1 ER - TY - JOUR AU - de Oliveira, Victor Hugo AU - Lee, Ines AU - Quintana-Domeque, Climent DA - 2021 PY - 2021 AB - We study the impacts of in utero exposure to Hurricane Catarina of March 2004, the first hurricane to hit Brazil. Catarina was unexpected and is representative of other recent hurricanes in the Americas in terms of wind speed, direct economic costs, and population affected. We use a triple differences strategy (close vs. far municipality, 2004 vs. 2003, after March vs. before) to highlight the importance of accounting for flexible season of birth effects compared to a standard differences-in-differences strategy. Using administrative data, we find that average birth weight declined and post-neonatal mortality increased among babies exposed to the hurricane in utero. The adverse effects are driven by babies of younger mothers. Our documented impacts are not explained by reductions in employment or healthcare use. Maternal stress seems to be a plausible mechanism if younger women are more financially vulnerable to negative shocks, consistent with recent work highlighting the relationship between socioeconomic status, stress, and birth outcomes. Our findings are robust to various checks, including testing for pre-trends in infant health outcomes. DO - 10.3368/jhr.59.1.0816-8144r1 SN - 0022-166X T2 - Journal of Human Resources TI - Natural Disasters and Early Human Development: Hurricane Catarina and Infant Health in Brazil ID - ITEM-1 ER -