Contests between groups are plagued by intra-group externalities (freeriding). Yet, costless incentive schemes that entirely avoid free-riding within a group might not be desirable, neither individually nor socially. In contests among two groups, a relatively weak (i.e., small or unproductive)...

This research establishes that the emergence, prevalence, recurrence, and severity of intrastate conflicts in the modern era reflect the long shadow of prehistory. Exploiting variations across national populations, it demonstrates that genetic diversity, as determined predominantly during the...

I construct a theory of foreign interventions in which the preferences of the foreign country over alternative local groups are determined by each group's international economic ties. In equilibrium, the foreign country supports the group with which it has the strongest ties, since this is most...

We develop a theory of interstate conflict in which the degree of genealogical relatedness between populations has a positive effect on their conflict propensities because more closely related populations, on average, tend to interact more and develop more disputes over sets of common issues. We...

This paper examines conflicts in which performance is measured by the players' success or failure in multiple component conflicts, commonly termed "battlefields". In multi-battlefield conflicts, behavioral linkages across battlefields depend both on the technologies of conflict within each...

This paper reviews the most significant recent developments in the theory of trade agreements. The paper offers an integrated approach to evaluating trade agreements, and uses the approach to present results on preferential and multilateral trade agreements. The paper identifies also several...

Global trade contracted quickly and severely during the global crisis. This paper, using a unique dataset of French firms, matching together export data with firm-level credit constraints, shows that most of the 2008-2009 trade collapse is accounted by the unprecedented demand shock and by...

The unprecedented drop in international trade during the last quarter of 2008 and the first quarter of 2009 has mainly been analysed at the macroeconomic or sectoral level. However, exporters who are heterogeneous in terms of productivity, size or external financial dependence should be...

We augment the canonical neoclassical model of trade to allow for interstate disputes over land, oil, water, or other resources. The costs of such disputes in terms of arming depend on the trade regime in place. Under either autarky or free trade, the larger country (in terms of factor...

This paper examines the effect of trade integration and comparative advantage on one of a country's institutions, which in turn inuences its economic efficiency. The environment we explore is one in which a country's lower classes may revolt and appropriate wealth owned by a ruling elite. The...