近年来，随着经济的不断发展，人们收入逐年增加，生活水平不断提高，衣食住行中最大的问题“住”已成了人们生活中不可回避的大事。近十年来商品房价格只升不降，而且上涨幅度超过收入增长幅度，如从１９９３年到２００２年１０年中，家庭年收入平均增长了１倍，而不同地区、? In recent years, as the economy continues to develop, people’s incomes have been increasing year by year and their living standards have been continuously improved. “Living”, the biggest issue in the basic necessities of life, has become an unavoidable event in people’s lives. Over the past ten years, the price of commercial housing has risen only but not increased, and its rate of increase has surpassed the rate of increase in income. For example, from 1993 to 2002, the average annual household income has doubled. In different regions, however,