In this paper, we modify the method of Blanchard and Quah [American Economi
c Review 79 (1989) 655] in order to estimate a structural VAR model appropr
iate for a small open economy. In this way, we identify shocks to output an
d prices in the members of the two monetary unions that make up the African
CFA Franc Zone. The costs of monetary union membership will depend on the
extent to which price and output shocks are correlated across countries and
the degree of similarity in the long-run effects of the shocks on the macr
oeconomy. The policy conclusions depend on the relative importance of diffe
rent macroeconomic variables to policymakers and the speed with which a pol
icymaker is able to respond to a shock. (C) 2001 Elsevier Science B.V. All
rights reserved.