An international arbitrage pricing model with PPP deviations

This paper develops an intertemporal, international asset pricing model for use in applied theoretical and empirical research. An important feature of the model is that it incorporates both stochastic inflation rates and stochastic Purchasing Power Parity deviations (PPP). The model derives the equilibrium real return on assets, and obtains empirically tractable reduced form equations which can be used to examine such issues as capital market segmentation, currency substitution, exchange rate volatility, and the forward exchange market's risk premium. Mechanically, the model begins as a system of stochastic differential equations which describe the dynamic paths of a vector of state variables, prices, and PPP deviations. The state variables' intertemporal development determines the production and credit opportunities, and provides the model's fundamental dynamic nature. The model is shown to be consistent with the domestic-general equilibrium asset pricing models of Cox, Ingersoll, and Ross (1985) and Brock (1982). The model is applied to pricing forward exchange, and an empirically tractable equation of the risk premium is derived which will allow researchers to uncover the risk premium's economic determinants.