There must be a good word for legislation that produces exactly the opposite result that its supporters intend. I know, let’s call it a “boomerang bill.”

The anti-inversion legislation that Treasury Secretary Jack Lew advocated on September 7th is, unfortunately, a classic example of a boomerang bill.  It is intended to stop a feared tidal wave of corporate inversions–that’s a fancy technical term for when a U.S. company moves its headquarters to another country, often but not always for tax reasons.

In reality, anti-inversion legislation, at least as currently proposed, is likely to turn U.S.-based multinationals into hunted prey, selling out to foreign rivals. The proposed legislation basically draws up a roadmap for activist investors and foreign companies, showing them how to get access to the overseas cash of U.S. companies by buying them up and moving their headquarters out of the country.

How does that happen? Proponents of anti-corporate-inversion legislation are worried that the tax benefits of moving the headquarters of a U.S. multinational overseas are compelling–so compelling that if they allow a few companies to do it, a tidal wave will follow.

So to stop the flood, the legislation would require that any company that wants to “invert” show at least 50% foreign ownership in order to escape the U.S. tax system. That’s intended to stop companies such as Medtronic, which is planning to acquire the Irish company Covidien and move its headquarters to Ireland, while maintaining its existing operations in the U.S.

Now, there is much debate about whether Medtronic is making this move for strategic or tax reasons. But that’s not important.  The big problem is that the anti-inversion legislation does nothing to fix the underlying problem, which is the incredibly weird and broken U.S. corporate tax system.

Instead, the legislation encourages activist investors and foreign companies to work together to make takeover bids for U.S. multinationals with large amounts of cash outside of the country. No company, no matter how large, would be safe.

What’s the real solution here? America’s corporate tax system is broken, and you don’t fix a broken leg by applying a band-aid. For one, it has a higher corporate tax rate, 35%, than almost any other industrialized country.

Second, America taxes all income, foreign and domestic, of U.S.-headquartered companies at this higher rate, something almost no other country does.

Let me state for the record that I believe America is an awesome place to live and work. In particular, America’s history and culture as a wellspring of innovation makes it the best place to build a business in the world, bar none.  And I am gratified when I see foreign businesses open up factories, software labs, or R&D facilities in this country.

At the same time, I don’t necessarily like it when a U.S.-based company moves its headquarters overseas. Still, it’s a business decision, the same as when a foreign company takes tax breaks to open up a big plant, say, in Alabama or Kentucky.

The solution here is to fix the corporate tax system, not to enact a boomerang bill that will only make things worse.