The analysis and forecasting of developments in the U.S. economy have always played a critical role in the formulation of Canadian economic and financial policy. Thus, the Bank places considerable importance on generating internal forecasts of U.S. economic activity as an input to the Canadian projection. Over the past year, Bank staff have been using a new macroeconometric model, MUSE (Model of the U.S. Economy). The model is a system of estimated equations that describe, in a stock-flow framework, the interactions among the principal macroeconomic variables, such as gross domestic product (GDP), inflation, interest rates, and the exchange rate. The stock-flow equilibrium is fully described in MUSE. In steady state, the model defines specific values for all stocks, including capital stock, government debt, financial wealth, and net foreign assets.

In MUSE, most behavioural equations are governed by a polynomial adjustment cost (PAC) structure. This approach is widely used in the U.S. Federal Reserve Board's FRB/US model. By allowing for lags in the dynamic equations in the context of forward-looking rational expectations, the PAC approach strikes a balance between theoretical structure and forecasting accuracy. MUSE, therefore, makes an explicit distinction between dynamic movements caused by changes in expectations and those caused by adjustment costs. Moreover, GDP is decomposed into household expenditures, business investment, government spending, exports, and imports. Hence, MUSE can be used to predict the consequences of a wide variety of shocks to the U.S. economy.