A.

Globalization and the rules it generates confront legal scholarship with a number of intricate issues. One of these lies at the core of a hypothesis which has been debated for some time in the literature. According to this hypothesis, the legal vacuum left by nation states in the institutional organization of cross-border commerce has been filled by a variety of private governance mechanisms, with the result that regulatory responsibility has been taken over by private or hybrid actors. Testing this proposition requires analytical tools capable of discriminating between private ordering and public law-making. The private, or hybrid, governance regimes that would seem to be the hallmark of what is slowly emerging as global law are a Byzantine mixture of legal and social norms. Because of this, the foremost problem to be solved is that of deciding where to draw the line between legal and non-legal norms. Only if there are unequivocal criteria for distinguishing between law and non-law does it become possible to comprehend how hybrid regimes arise and evolve within the globalization process and, thus, to determine whether private actors have in fact assumed regulatory responsibility.

The explanations of global governance regimes most widely accepted today were worked out by institutionalist scholars. Institutionalism, however, does not discriminate between legal and non-legal norms. While it aptly explains how behavior regulation can work in the absence of state law, it does not draw any distinction between the mechanisms that generate law and those that engender social norms. This places the issue at hand beyond the explanatory reach of institutionalism. This is not to say, however, that institutionalism is irrelevant to the issue. A closer look at the analytical tools it has developed may perhaps provide useful guidance in unraveling the law/non-law conundrum.

Of all the branches of New Institutionalism, rational choice institutionalism is the one that has placed the problem of norm genesis and evolution most...