A TIDD, or tax increment development district, is a public financing method that has been used in the U.S. for more than 50 years. Originally it was intended for redeveloping blighted urban areas. But in recent years, it has been used for projects on undeveloped land. This is the case with the SunCal project on the West Mesa in Albuquerque.

In a TIDD, the current tax base is measured in the district. The developer gets a percentage of the increase in taxes over that current tax base in the future. The idea is that the project and infrastructure built for the project will spark growth in the area.

SunCal currently has nine TIDDs on Albuquerque's West Mesa, covering about 4,000 acres of its total 55,000 acres. Bernalillo County has agreed to give the company about 30 percent of its gross receipts tax revenue from within each district and 10 percent of county property tax revenue for up to 28 years. SunCal wants the state to give the company the ability to sell bonds worth up to $408 million to finance the building of roads, utilities and other infrastructure in that 4,000 acres.

SunCal and other advocates of TIDDs say the method is a good way to create desirable developments and jobs. SunCal's Web site promises 1,400 construction jobs, 11,220 high-tech jobs and 280 retail jobs.

But opponents, who include an unlikely alliance of environmentalists and conservatives, say TIDDs lead to urban sprawl, take existing businesses out of their current locations, adversely affect tax revenues and amounts to the government funding private businesses.