The most recent Case-Shiller Home Price Index, which tracks residential real estate in the country’s major metropolitan areas, shows that, by one measure, the housing collapse hit Chicago harder than many other cities. Over the past four years (from November 2006 to November 2010, the latest date for which information was available), prices here dropped by 28.9 percent; over that same period, the average drop in the top 20 U.S. cities was 29.7 percent. But from 2000 to 2006, when the top 20 cities saw an average increase in price of 84.7 percent, prices here rose by only 56.5 percent—meaning that, when the downturn came, there were fewer gains to erode in the Chicago area.