Assume the model Y = C + I + G + X - M, where C = a + bYd and Yd=Y - Tx; Tx is exogenous; I = f( i but MPI = 0; G = Go and X = Xo; M = Mo + mY; Money supply is exogenously determined; Md = Mt + Ml with Mt=f(Y) and Ml=f(i) Now, assume there is an autonomous increase in the level of exports. This would result in: an increase in aggregate income a decrease in aggregate income no change in aggregate income an income change of indeterminant direction