General equilibrium with trade balance and real interest rate parity

Abstract.

This paper demonstrates, in the context of a two-sector OLG neoclassical growth model, conditions under which international trade in consumption goods alone may be sufficient for the equalization of real returns to physical capital across countries; that is, under which commodity arbitrage is sufficient for real interest rate parity (RIRP). This role for repeated commodity arbitrage is established via a dynamic extension of the factor price equalization (FPE) theorem which is valid at all dates comprising the equilibrium path as well as its steady state. The results are at odds with the conventional view regarding RIRP which arises from open one-sector growth models, in which case steady state trade balance and RIRP are irreconcilable, and are also a contradiction to frequent assertions of lon-run specialization in two-sector frameworks. An equilibrium path for an integrated world economy yields an endogenous, time-variant cone of diversification which implies sufficient conditions for the dynamic paths of a cross-section of economies to exhibit FPE, and hence RIRP with trade balance, at all points in time. These conditions require that the savings rates and initial capital-labor ratios of individual countries do not deviate too significantly from world averages, and that both sectors absorb capital easily. The first of these requirements is sufficient to establish steady state FPE and RIRP in the general specification. The first two requirements are sufficient for the entire equilibrium path to be characterized by FPE and RIRP in a log-linear example.