Structural dynamics and spatial analysis: from equilibrium balancing models to extended economic models for both perfect and imperfect markets.

The equilibrium balancing model developed by Harris and Wilson (1978) is now being widely applied. In this paper, two extensions are presented: 1) to show how that model can be made more explicitly 'economic' through the introduction of prices and low rents; 2) to show how an entropy-maximizing model of the structural variables can be developed to represent imperfect markets. For clarity and ease of presentation, the ideas are developed in relation to the simplest possible models in which they can be represented, but there are obvious extensions to more complicated and realistic cases.-Author