Reuven S. Avi-Yonah (Michigan) has posted Money on the Table: Why the U.S. Should Tax Inbound Capital Gains on SSRN. Here is the abstract:

In 1992, Chairman Rostenkowski introduced legislation that imposed U.S. capital gains tax on foreign sellers of large blocks of shares (10% or more) in U.S. corporations. The legislation was not a treaty override, although it added an anti-treaty shopping provision similar to those adopted for the branch profit tax in 1986. It also had anti-abuse provisions that addressed holding company structures. Today, the U.S. faces a large budget deficit and seeks to impose higher burdens on its own multinationals. While that is also justified, there is no reason to let foreigners off the hook, especially since there is much more inbound FDI now than there was in 1992. Congress should adopt the Rostenkowski legislation now.