On the Theory of Ethnic Conflict

We present a theory of ethnic conflict in which coalitions formed along ethnic lines compete for the economy’s resources. The role of ethnicity is to enforce coalition membership: in ethnically homogeneous societies members of the losing coalition can defect to the winners at low cost, and this rules out conflict as an equilibrium outcome. We derive a number of implications of the model relating social, political, and economic indicators such as the incidence of conflict, the distance among ethnic groups, group sizes, income inequality, and expropriable resources.

On the Theory of Ethnic Conflict

We present a theory of ethnic conflict in which coalitions formed along ethnic lines compete for the economy's resources. The role of ethnicity is to enforce coalition membership: in ethnically homogeneous societies members of the losing coalition can defect to the winners at low cost, and this rules out conflict as an equilibrium outcome. We derive a number of implications of the model relating social, political, and economic indicators such as the incidence of conflict, the distance among ethnic groups, group sizes, income inequality, and expropriable resources.ethnic distance, exploitation

The World Technology Frontier

We define a country's technology as a triple of efficiencies: one for unskilled labor, one for skilled labor, and one for capital. We find a negative cross-country correlation between the efficiency of unskilled labor and the efficiencies of skilled labor and capital. We interpret this finding as evidence of the existence of a World Technology Frontier. On this frontier, increases in the efficiency of unskilled labor are obtained at the cost of declines in the efficiency of skilled labor and capital. We estimate a model in which firms in each country optimally choose from a menu of technologies, i.e. they choose their technology subject to a Technology Frontier. The optimal choice of technology depends on the country's endowment of skilled and unskilled labor, so that the model is one of appropriate technology. The estimation allows for country-specific technology frontiers, due to barriers to technology adoption. We find that poor countries tend disproportionately to be inside the World Technology Frontier.

On the Theory of Ethnic Conflict

We present a theory of ethnic conflict in which coalitions formed along ethnic lines compete for the economy%u2019s resources. The role of ethnicity is to enforce coalition membership: in ethnically homogeneous societies members of the losing coalition can defect to the winners at low cost, and this rules out conflict as an equilibrium outcome. We derive a number of implications of the model relating social, political, and economic indicators such as the incidence of conflict, the distance among ethnic groups, group sizes, income inequality, and expropriable resources.

Cross-Country Technology Diffusion: The Case of Computers

We use data on imports of computer equipment for a large sample of countries between 1 970 and 1990 to investigate the determinants of computer-technology adoption. We find strong evidence that computer adoption is associated with higher levels of human capital and with manufacturing trade openness vis-a-vis the OECD. We also find evidence that computer adoption is enhanced by high investment rates, good property rights protection, and a small share of agriculture in GDP. Finally, there is some evidence that adoption is reduced by a large share of government in GDP, and increased by a large share of manufacturing. After controlling for the above-mentioned variables, we do not find an independent role for the English- (or European-) language skills of the population.

On the theory of ethnic conflict

We present a theory of ethnic conflict in which coalitions formed along ethnic lines compete for the economy’s resources. The role of ethnicity is to enforce coalition membership: in ethnically homogeneous societies members of the losing coalition can defect to the winners at low cost, and this rules out conflict as an equilibrium outcome. We derive a number of implications of the model relating social, political, and economic indicators such as the incidence of conflict, the distance among ethnic groups, group sizes, income inequality, and expropriable resources

On the theory of ethnic conflict

When considering engaging in conflict to secure control of a resource, a group needs to predict the amount of post-conflict leakage due to infiltration by members of losing groups. We use this insight to explain why conflict often takes place along ethnic lines, why some ethnic groups are more often in conflict than others (and some never are), and why the same groups are sometimes in conflict and sometimes at peace. In our theory ethnic markers help enforce group membership: in homogeneous societies members of the losing group can more easily pass themselves as members of the winning group, and this reduces the chances of conflict as an equilibrium outcome. We derive a number of implications of the model relating social, political, and economic indicators such as the incidence of conflict, the distance between ethnic groups, group sizes, income inequality, and expropriable resources. One of the insights is that the incidence of ethnic conflict is nonmonotonic in expropriable resources as a fraction of total resources, with a low incidence for either low or high values. We use the model’s predictions to interpret historical examples of conflict associated with skin pigmentation, body size, language, and religion

How regions converge

We present a joint study of the US structural transformation (the decline of agriculture as the dominating sector) and regional convergence (of Southern to Northern average wages). We find that empirically most of the regional convergence is attributable to the structural transformation: the nation-wide convergence of agricultural wages to non-agricultural wages and the faster rate of transition of the Southern labour force from agricultural to nonagricultural jobs. Similar results describe the Mid-West’s catch up to the North- East (but not the relative experience of the West). To explain these observations, we construct a model in which the South (Mid-West) has a comparative advantage in producing (unskilled) labour-intensive agricultural goods. Thus, it starts with a disproportionate share of the unskilled labour force and lower per capita incomes. Over time, declining education/training costs induce an increasing proportion of the labour force to move out of the (unskilled) agricultural sector and into the (skilled) non-agricultural sector. The decline in the agricultural labour force leads to an increase in relative agricultural wages. Both effects benefit the South (Mid-West) disproportionately since it has more agricultural workers. With the addition of a less-than-unit income-elasticity of demand for farm goods and faster technological progress in farming than outside of farming, this model successfully matches the quantitative features of the US structural transformation and regional convergence, as well as several other stylized facts on US economic growth in the last century. The model does not rely on frictions on inter-regional factor mobility, since in our empirical work we find this channel to be less important than the compositional effects the model emphasizes