“Enterprise zones” have an intuitive appeal. Flood a poor area with all sorts of aid to attract business. Create thriving little Hong Kongs in places of despair, particularly urban areas, through the miracle of free enterprise. Some folks, especially on the right, have suggested turning Detroit in a giant, low-tax enterprise zone. And President Obama has proposed his own version, “promise zones.” More from the San Francisco Fed:

Federal Empowerment Zones consist of relatively poor, high-unemployment Census tracts. They offer businesses tax credits of up to $3,000 per worker for hiring zone residents and (in the original zones) block grants of up to $100 million to be used for business assistance, infrastructure investment, and training programs. Benefits vary across state programs, but many also emphasize hiring credits.