New data paints a picture of land prices across the U.S.

Historic land-versus-construction cost data creates a detailed portrait of how far and where land and home prices have fallen.

For years, the rule of thumb ratio for land-versus-home construction costs has been one to four or one to three, but a new data base published by the Wisconsin School of Business shows just how widely that ratio varies across the country and how drastically it changed in many markets during the housing boom and consequent bust.

The free data, developed by the Lincoln Institute of Land Policy and the Graaskamp Center for Real Estate at the Wisconsin School of Business, can be accessed at http://www.lincolninst.edu/subcenters/land-values/.

"If housing were simply a manufactured good, and location or land had no value, then the price of housing would be determined by construction costs, and housing prices would increase at roughly the same rate as the price of other goods in the U.S. economy," said Morris A. Davis, an assistant professor of Real Estate and Urban Land Economics at the Wisconsin School of Business and fellow at the Lincoln Institute.