Tax on vacant home?

http://en.stockbiz.vn/News/2011/5/27/213662/new-penalties-on-unused-homes-under-considerations.aspx

Summary:
The government propose a tax on homes or land that are left empty for a particular period (three months). The purpose of the tax is to avoid land wasting, which will drive the real estate market even crazier.

My Take:

It sounds like a good idea to me as long as it is executed properly. Here are some effects of the tax on the real estate market:
- Vacant home and land owner will have incentives to finish their home. More finished homes in the market means more supply as they will be rented out. And the increased supply of homes will stabilize the market.
- Those owners that can't afford to finish the home may have the option of selling it to those who is more willing to build and finish the home. In general, this shift the ownerships of homes to those who can build and finish it. And it will increase supple... bla bla bla.

A purely good tax should not create any inefficiencies (dead weight loss) and it should fix the market when the "invisible hand" doesn't guide people. In other words, individually beneficial actions sometimes don't result in public good. Tax is there to fix it. This tax seem to do that.

However, I am not buying that the gov will be able to execute it well. We live in a corrupting culture. Students know how to cheat since they got 8; adults know how to give kickbacks to polices on streets... Somehow, people will be able to go around this tax. In addition, finding out where vacant homes are and tracking their owners will be complicated and expensive tasks.