The authors analyze the relationship between ethnic polarization and the duration of civil wars. Several recent papers have argued that the uncertainty about the relative power of the contenders in a war will tend to increase its duration. In these models, uncertainty is directly related to the...

The World Health Organization estimates that 300 million clinical cases of malaria occur annually and also observed that during the 80's and part of the 90's its incidence increased noticably. There are basically two factors behind the incidence of malaria: 'geographical destiny' and...