We study an exchange rule decomposability property requiring that if a frac
tion only of a recommended exchange takes place, then the remaining exchang
e be also recommended when including already exchanged quantities in indivi
dual endowments. We obtain justifications for the Walrasian exchange rule a
lthough this rule is not the only efficient, decomposable and equitable exc
hange rule. (C) 2001 Elsevier Science B.V. All rights reserved.