SOUNDING more like a cartographer than a central banker, Ben Bernanke this week showed off the Federal Reserve’s latest gizmo for tracking America’s property bust: maps that colour-code price declines, foreclosures and other gauges of housing distress for every county. His goal was to show that falling prices meant more foreclosures, and to urge lenders to write down the principal on troubled loans where the house is worth less than the value of the mortgage. His maps—where hotter colours imply more trouble—also make a starker point. The pain of America’s housing bust varies enormously by region. Hardest hit have been the “bubble states”—California, Nevada and Florida, and parts of the industrial Midwest. The biggest uncertainty hanging over the economy is how red will things get.