 Claim (I) differs from claim (IV). The explanatory claim asserts that (some) legal rules and institutions induce efficient behavior but does not identify the mechanism through which this efficient behavior results. The behavioral claim, by contrast, identifies the mechanisms through which legal rules and institutions influence behavior, but it does not assert that the resulting behavior is  efficient.[3]  Claims (II) and (III) are equally silent about the mechanisms that yield efficiency though one might think that claim (II) asserts that judges and other public officials intentionally pursue efficient rules. 