Ew. Bond et C. Syropoulos, THE SIZE OF TRADING BLOCS - MARKET POWER AND WORLD WELFARE EFFECTS, Journal of international economics, 40(3-4), 1996, pp. 411-437
We construct an n-country n-commodity trade model to analyze the impli
cations of bloc size for (Nash) equilibrium tariffs and welfare. The r
elationship between the absolute size of (symmetric) trading blocs and
their market power is ambiguous, and we illustrate how this relations
hip varies with model parameters. In contrast, sufficiently large incr
eases in the relative size of a bloc enhance its relative market power
and cause the welfare of its country members to rise above the free t
rade level. We establish the existence of an optimal bloc size, and st
udy the dependence of optimal size on the parameters of the model.