The rise and fall of regional inequalities

This paper analyses how the degree of regional integration affects regional differences in production structures and income levels. With high transport costs, industry is spead across regions to meet final consumer demad. As transport costs fall, increasing returns interacting with labour mobility and/or inout-output linkages between firms create a tendency for the agglomeration of increasing returns activities. When workers migrate towards locations with more firms and higher real wages, this intensifies agglomeration. When instead workers do not move across regions, further reductions in transport costs make firms increasingly sensitive to wage differentials, leading industry to spread out again.