For two years, the homebuyer credit has been in the running for Washington’s worst tax policy idea. Now, new evidence about this bit of legislative bilge suggests it may be time to retire the trophy. The Commerce Department reports the new homes market collapsed in May after booming in March and April (chart). Why? Well, in early spring, in response to an intense marketing campaign by the real estate and mortgage industries, tens of thousands of buyers accelerated home purchases to take advantage of this sweet tax give-away (as much as $8,000 for some buyers) before the credit expired on April 30. Then, just as most sentient economists predicted, the market dried up. Actually, it didn’t just dry up. It became the Death Valley of housing.