The taxation of cross-border savings income and the quality and cost of information exchanged

Today a key word in almost every debate about international taxation, both in academic and political circles, is information exchange (IE). That is the case for the taxation of multinational entreprises and also for that of savings income. In this paper we focus on that latter: both the European Union Directive and the US QualiÖed Intermediary (QI) and Foreign Account Tax Compliance Act (FATCA) mechanisms are based on that principle. Especially we attempt to answer, or at least to highlight, two questions. First why did the US move from unilateral to reciprocal exchange of information? And second, which governments Önd their best interest in participating to that cooperative device proposed by the US authorities? We look at those questions assuming that acquering information is costly.