How Much War Will we see?

Quantitative studies of civil war have focused on war initiation (onset) or war duration and termination and produced important insights into these processes. An empirical analysis of civil war prevalence is used to show that the prevalence or amount of war observed at any given time is important. Civil war prevalence is defined as the probability of observing either a new war onset or the continuation of an ongoing war or both. Two economic theories of war onset and duration are combined to estimate the prevalence of civil war across more than 150 countries and over 40 years. The analysis is consistent with the findings of earlier studies on war onset and duration. New findings that result from slight improvements in the data and estimation methods show that democracy and ethnic diversity are significant determinants of civil war prevalence.