In Boston Stock Exchange v. State Tax Comm'n, 429 U.S. 318, 336-37, 97 S.Ct. 599, 50 L.Ed.2d 514 (1977), the Supreme Court held unconstitutional amendments to New York's securities transfer tax that aimed to offset the competitive advantage that the transfer tax otherwise created for out-of-state exchanges that did not tax transfers. See Boston Stock Exchange, 429 U.S. at 323 - 24, 97 S.Ct. 599. Prior to the amendment, New York uniformly taxed in-state transfers of securities without regard to the place of sale. See id. at 322, 97 S.Ct. 599. The amendment created a 50 percent reduction in the tax rate on transfers by nonresidents and limited liability on transfers of large blocks of shares as long as the sales were made in New York. See id. at 324, 97 S.Ct. 599. As a result, the amendment caused transactions involving out-of-state sales to be taxed more heavily than transactions involving in-state sales. See id. at 330 - 31, 97 S.Ct. 599. The Court held that the reduction offended the Commerce Clause's anti-discrimination principle by converting a tax that was previously "neutral as to in-state and out-of-state sales" into one that which would induce a seller to trade through a New York broker in order to reduce its tax liability. See id. at 330-32, 97 S.Ct. 599. In doing so, New York effectively "foreclosed tax-neutral decisions" and "created both an advantage for the exchanges in New York and a discriminatory burden on commerce to its sister States." Id. at 331, 97 S.Ct. 599. The diversion of interstate commerce from the most economically efficient channels that resulted from New York's use of "its power to tax an in-state operation as a means of `requiring other business operations to be performed in the home state,'" id. at 336, 97 S.Ct. 599 (quoting Pike v. Bruce Church, Inc., 397 U.S. 137, 145, 90 S.Ct. 844, 25 L.Ed.2d 174 (1970)), was seen by the Court as "wholly inconsistent with the free trade purpose of the Commerce Clause."