The fluctuations in incomes inherent in rural communities can be attenuated by reciprocal assistance. A model of reciprocal assistance based upon rational action and voluntary participation is presented. Individuals provide assistance only if the costs of so doing are outweighed by the benefits...

We focus on the coordination failure among domestic firms in the investment of expensive low-carbon technology, which helps reduce the amount of carbon usage and pollution. In this model the firms are charged with a carbon tax only if the total stock of carbon emission in the environment exceeds...