THE NONSUBSTITUTION AND NONSWITCHING THEOREMS IN A MODEL WITH FIXED CAPITAL.

Let a competitive economy produce commodities of varying durabilities, such that a production processes exhibit constant returns to scale b there is one exogenous non-productible factor c there are alternative techniques to produce each good d it is possible to define conversion coefficients for old durable goods in terms of new goods of the same kind. Theorem Let A-d hold. Then I A long-run equilibrium of input-output coefficients and of prices in terms of wage units is uniquely determined for any preassigned value of the rate of interest. II It is impossible to have identical techniques at different interest rates. This theorem generalizes Samuelsons static and dynamic nonsubstitution theorem. Author