Treating exchange rates as the only exogenous U.S.- macroeconomic variable, many studies are able to unambiguously predict the effects of changes in the value of the dollar on the volume, price, and share of U.S. grain exports and government program expenses. Using the neo-Keynesian paradigm, this study develops a theoretical framework to assess the overall impact of changes in U.S. macroeconomic policy on the same variables via real income, interest and exchange rates, and the general price level. The analysis demonstrates that the shortrun impacts cannot be always unambiguously predicted. The direction of the impacts are shown to be crucially dependent on (1) the initial equilibrium point, (2) the extent of the linkage variable responses, and (3) relative magnitudes of price and real income elasticities of domestic demand, the real interest elasticity of domestic supply, and the price elasticity of export demand curves.