While transport costs have fallen, the empirical evidence also points at rising total trade costs. In a model of industry location with endogenous transaction costs, we show how and under which conditions a decline in transport costs can lead to an increase in the total cost of trade.

This paper argues that existing models of urban concentrations are incomplete unless grounded in the most fundamental aspect of proximity; face-to-face contact. Face-to-face contact has four main features; it is an efficient communication technology; it can help solve incentive problems; it can...