Model Constructions and the Market Economy

Lachmann’s 1966 essay is a methodological defense of the market economy as a process of meaningful action, not a closed system of formal relations. He grants that economic theory must abstract, but argues that much modern model construction abstracts from the very phenomena that make markets intelligible: plans, expectations, disappointment, revision, and entrepreneurial interpretation. The task is therefore not to derive ideal price vectors from assumed data, but to understand how actors, each with partial knowledge, orient themselves within changing market signals.

To explain market phenomena therefore means to analyze these phenomena in terms of their meaningful components.

Against equilibrium formalism, Lachmann insists that the market cannot be understood as if all relevant knowledge were already assembled in one mind. Linear models, growth paths, and welfare constructions often assume precisely what the market exists to coordinate: dispersed, inconsistent, and revisable knowledge. Their elegance comes at the cost of excluding error, discovery, and plan revision. The market economy is not a mechanism for realizing a pre-known optimum, but an institutional setting in which incompatible expectations are tested and reworked.

The reason is that no individual actor in the market actually possesses that total knowledge of the data that linear theory assumes.

This critique is sharpest in Lachmann’s discussion of growth theory. He rejects the treatment of the economy as a single optimizing subject moving along a maximum growth path. Such models conceal the heterogeneity of capital, the changing structure of production, and the uncertainty under which investment decisions are made. What appears retrospectively as technological progress or balanced growth is prospectively a field of conjectural plans, some of which succeed and others of which are revealed as malinvestments. For Lachmann, the explanatory unit is not the aggregate but the plan, because plans connect subjective interpretation to observable market movement.

Central to all activities of the market economy is the individual economic plan.

The constructive side of the essay is Lachmann’s call for an “open” and genetic-causal theory of the market economy. Market events matter because actors interpret them; prices, profits, losses, and capital values are not merely variables in a system but signals that alter expectations and redirect action. Capital especially embodies expectations about future uses and yields. Its valuation changes as plans are confirmed or disappointed, so the distribution of wealth is not simply a background condition but a continuing result of market judgment.

Lachmann’s treatment of competition follows the same logic. He rejects the textbook ideal of perfect competition because it eliminates the inequalities, initiatives, and differences through which competition actually works. Rivalry consists in innovation, product differentiation, imitation, and the erosion of temporary advantages. The market’s virtue is not that all actors face identical conditions, but that buyers and sellers encounter alternatives and learn from unequal performances.

The essay’s larger significance lies in its Austrian and subjectivist reconstruction of market theory. Lachmann moves from equilibrium states to market processes, from objective data to interpreted knowledge, from maximization to revision, and from aggregate growth to capital revaluation. His target is not theory itself but a style of theory that mistakes formal closure for explanation.

Dynamic equilibria, maximum growth paths, and similar concepts are notions of economists with little interest in what matters in the market economy.