This paper develops a simple model of a polluting industry and an innovating firm. The polluting industry is faced with regulation and costly abatement. Regulation may be taxes or marketable permits. The innovating firm invests in R&D and develops technologies which reduce the cost of pollution...

Recovery of causal relationships in data is an essential part of scholarly inquiry in the social sciences. This chapter discusses strategies that have been successfully used in urban and regional economics for recovering such causal relationships. Essential to any successful empirical inquiry is...

Geography shapes economic outcomes in a major way. This paper uses spatial empirical methods to detect and analyze trade patterns in a historical data set on Chinese rice prices. Our results suggest that spatial features were important for the expansion of interregional trade. Geography...

Recent models in economic geography suggest that there may be very large numbers of equilibrium spatial structures. Simulations suggest, however, that the structures that emerge are surprisingly orderly, and often seem approximately to follow simple rules about the spacing of urban sites. This...

The observed uneven distribution of economic activity across space is influenced by variation in exogenous geographical characteristics and endogenous interactions between agents in goods and factor markets. Until recently, the theoretical literature on economic geography had focused on stylized...