This paper considers a dynamic model of innovations in which firms can endogenously bias the direction of technological change. Both in a North–North and North–South context, we show that, when globalization triggers an increased threat of technological leapfrogging or imitation, firms tend to respond to that threat by biasing the direction of their innovations towards skilled-labor-intensive technologies. We show that this process of defensive skill-biased innovations generates an increase in wage inequalities in both regions. We then discuss suggestive empirical evidence of the existence of defensive skill-biased technical change.

This paper analyses theoretically and empirically the relationship between military conflicts and trade. We show that the conventional wisdom that trade promotes peace is only partially true even in a model where trade is economically beneficial, military conflicts reduce trade, and leaders are rational. When war can occur because of the presence of asymmetric information, the probability of escalation is lower for countries that trade more bilaterally because of the opportunity cost associated with the loss of trade gains. However, countries more open to global trade have a higher probability of war because multilateral trade openness decreases bilateral dependence to any given country and the cost of a bilateral conflict. We test our predictions on a large data set of military conflicts on the 1950–2000 period. Using different strategies to solve the endogeneity issues, including instrumental variables, we find robust evidence for the contrasting effects of bilateral and multilateral trade openness. For proximate countries, we find that trade has had a surprisingly large effect on their probability of military conflict.

Quantifications of gains from trade in heterogeneous firm models assume that productivity is Pareto distributed. Replacing this assumption with log-normal heterogeneity retains some useful Pareto features, while providing a substantially better fit to sales distributions-especially in the left tail. The cost of log-normal is that gains from trade depend on the method of calibrating the fixed cost and productivity distribution parameters. When set to match the size distribution of firm sales in a given market, the log-normal assumption delivers gains from trade in a symmetric two-country model that can be twice as large as under the Pareto assumption.

Abstract We investigate the impact of climate shocks on farmer-herder violence, using geolocalized data on conflict events for Africa, 1997-2014. We find that a one degree temperature increase yields a 54% increase in conflict probability in mixed areas populated by both farmers and herders (versus 17% in non-mixed areas). Quantifying the impact of projected climate change in 2040, we find that -when factoring in the magnifying effect of mixed settlements- annual conflicts are predicted to rise by a third. Drawing on a fine-grained analysis of groups' mobility patterns, we show that resource competition is a major driver of farmer-herder violence.

We study how news coverage of immigrant criminality impacts voting in one of the most controversial referendums in recent years—the 2009 Swiss minaret ban. We combine a comprehensive crime detection data set with detailed information on newspaper coverage. We first document a large upward distortion in media reporting of immigrant crime during the prereferendum period. Exploiting quasi-random variations in crime incidence, we find a positive first-order effect of news coverage on support for the ban. Our quantification shows that, in absence of the media bias, the pro-ban vote would have decreased from 57.6% to 53.5% at the national level.

We estimate the push and pull factors involved in the outmigration of Jews facing persecution in Nazi Germany from 1933 to 1941. Our empirical investigation makes use of a unique individual-level data set that records the migration history of the Jewish community in Germany over the period. Our analysis highlights new channels, specific to violent contexts, through which social networks affect the decision to flee. We estimate a structural model of migration where individuals base their migration decision on the observation of persecution and migration among their peers. Identification rests on exogenous variations in local push and pull factors across peers who live in different cities of residence. Then we perform various experiments of counterfactual history to quantify how migration restrictions in destination countries affected the fate of Jews. For example, removing work restrictions for refugees in the recipient countries after the Nuremberg Laws (1935) would have led to an increase in Jewish migration out of Germany in the range of 12% to 20% and a reduction in mortality due to prevented deportations in the range of 6% to 10%.

We study empirically how past exposure to conflict in origin countries makes migrants more violence-prone in their host country, focusing on asylum seekers in Switzerland. We exploit a novel and unique dataset on all crimes reported in Switzerland by the nationalities of perpetrators and of victims over 2009–2016. Our baseline result is that cohorts exposed to civil conflict/mass killing during childhood are 35 percent more prone to violent crime than the average cohort. This effect is particularly strong for early childhood exposure and is mostly confined to co-nationals, consistent with inter-group hostility persisting over time. We exploit cross-region heterogeneity in public policies within Switzerland to document which integration policies are best able to mitigate the detrimental effect of past conflict exposure on violent criminality. We find that offering labor market access to asylum seekers eliminates two-thirds of the effect. (JEL D74, F22, K42, Z18)

We combine georeferenced data on mining extraction of 14 minerals with information on conflict events at spatial resolution of 0.5 o × 0.5 o for all of Africa between 1997 and 2010. Exploiting exogenous variations in world prices, we find a positive impact of mining on conflict at the local level. Quantitatively, our estimates suggest that the historical rise in mineral prices (commodity super-cycle) might explain up to one-fourth of the average level of violence across African countries over the period. We then document how a fighting group's control of a mining area contributes to escalation from local to global violence. Finally, we analyze the impact of corporate practices and transparency initiatives in the mining industry. (JEL C23, D74, L70, O13, Q34)

We study from both a theoretical and an empirical perspective how a network of military alliances and enmities affects the intensity of a conflict. The model combines elements from network theory and from the politico-economic theory of conflict. We obtain a closed-form characterization of the Nash equilibrium. Using the equilibrium conditions, we perform an empirical analysis using data on the Second Congo War, a conflict that involves many groups in a complex network of informal alliances and rivalries. The estimates of the fighting externalities are then used to infer the extent to which the conflict intensity can be reduced through (i) dismantling specific fighting groups involved in the conflict; (ii) weapon embargoes; (iii) interventions aimed at pacifying animosity among groups. Finally, with the aid of a random utility model, we study how policy shocks can induce a reshaping of the network structure.

We study how the spread of the Lost Cause narrative—a revisionist and racist retelling of the US Civil War—shifted opinions and behaviors toward national reunification and racial discrimination against African Americans. Looking at screenings of The Birth of a Nation, a blockbuster movie that greatly popularized the Lost Cause after 1915, we find that the film shifted the public discourse toward a more patriotic and less divisive language, increased military enlistment, and fostered cultural convergence between former enemies. We document how the racist content of the narrative connects to reconciliation through a “common-enemy” type of argument. (JEL J15, L82, N31, N32, N41, Z13)