This article explores empirically the duration of civil war. It relates the duration of civil war to two alternative models of conflict and culls testable hypotheses from the case study literature on civil war. Using a comprehensive dataset on large-scale violent civil conflicts covering the 1960-2000 period, a wide range of hypotheses are tested by means of hazard function regressions. The results show that the duration of conflict is systematically related both to structural conditions prevailing prior to conflict and to circumstances during conflict. The key structural characteristics that lengthen conflict are low per capita income, high inequality and a moderate degree of ethnic division. The key variable characteristics that shorten conflict are a decline in the prices of the primary commodities that the country exports and external military intervention on the side of the rebels. Furthermore, the results indicate that the chances of peace were much lower in the 1980s and 1990s than they had been previously. Three empirical explanations are suggested as different approaches to civil war: rebellion-as-investment, in which the critical incentive is the post-conflict payoff; rebellion-as-business, in which the critical incentive is the payoff during conflict; and rebellion-as-mistake, in which military optimism prevents the recognition of any mutually advantageous settlement. The article concludes that the empirical evidence is incompatible with the first of these approaches but consistent with the others.

Post-conflict societies face two distinctive challenges: economic recovery and reduction of the risk of a recurring conflict. Aid and policy reforms have been found to be effective in economic recovery. In this article, the authors concentrate on the other challenge — risk reduction. The post-conflict peace is typically fragile: nearly half of all civil wars are due to post-conflict relapses. The authors find that economic development substantially reduces risks, but it takes a long time. They also find evidence that UN peacekeeping expenditures significantly reduce the risk of renewed war. The effect is large: doubling expenditure reduces the risk from 40% to 31%. In contrast to these results, the authors cannot find any systematic influence of elections on the reduction of war risk. Therefore, post-conflict elections should be promoted as intrinsically desirable rather than as mechanisms for increasing the durability of the post-conflict peace. Based on these results, the authors suggest that peace appears to depend upon an external military presence sustaining a gradual economic recovery, with political design playing a somewhat subsidiary role. Since there is a relationship between the severity of post-conflict risks and the level of income at the end of the conflict, this provides a clear and uncontroversial principle for resource allocation: resources per capita should be approximately inversely proportional to the level of income in the post-conflict country.

We use firm-level panel data for the manufacturing sector in four African countries to investigate whether exporting impacts on efficiency, and whether efficient firms self-select into the export market. Based on simultaneous estimation of a production function and an export regression, our preferred results indicate significant efficiency gains from exporting, which can be interpreted as learning by exporting. We show that modelling unobserved heterogeneity by a flexible approach is important for deriving this conclusion. A policy implication of our results is that Africa would gain from orientating its manufacturing sector towards exporting.

Cobb Douglas production function parameters are not identi…ed from crosssection variation when inputs are perfectly ‡exible and chosen optimally, and input prices are common to all …rms. We consider the role of adjustment costs for inputs in identifying these parameters in this context. The presence of adjustment costs for all inputs allows production function parameters to be identi…ed, even in the absence of variation in input prices. This source of identi…cation appears to be quite fragile when adjustment costs are deterministic, but more useful in the case of stochastic adjustment costs. We illustrate these issues using simulated production data.JEL Classi…cation: D20, D24, C23.Key words: Production functions, adjustment costs, identi…cation.Acknowledgement: This paper is dedicated to the memory of Tor Jakob Klette, a …ne scholar and an inspiration to those who knew him. We thank Victor Aguirregabiria, Bronwyn Hall, participants in a conference at the University of Oslo and a seminar at the University of Göteborg for helpful comments.