China has formally overtaken Japan as the world's second largest economy. Yet, for all the recent excited commentary, there's less cause for baijiu toasts in Beijing than they might think. That's because China's economic growth has followed what's sometimes called "the Japanese model." In Japan and other Asian countries, this model has proved extraordinarily successful in the short term in generating eye-popping rates of growth -- but it always eventually runs into the same fatal constraints: massive overinvestment and misallocated capital. And then a period of painful economic adjustment. In short: Beijing, beware.