中国经济高增长还能持续多久——基于拓展的索洛模型的预测

How Long Can China's Rapid Economic Growth Sustained——Forecast Based on the Expanded Solow Model

靠长期刺激投资高增长来维持经济增速是不可行的。不断下降的资本利润率最终导致私人部门投资意愿缺乏。在开放的经济条件下,资本将大量外流寻找利润更高的栖息之地。索洛模型未考虑资本跨国境流动对分析对象的影响。在拓展模型中,经济体系由两个部分组成:一个为发达国家,已实现平衡增长,低储蓄率;另一个为后发型国家,处于追赶阶段,高储蓄率。随着"产出—资本比"变化,后发型国家的资本利润率优势将逐渐消失,其追赶进程可分为三个阶段:第Ⅰ阶段——外资流入;第Ⅱ阶段——资本流出;第Ⅲ阶段——平衡增长。第二阶段起点是人均资本增长路径的转折点,人均资本增速将在该点陡然下降。这势必导致人均产量增速在转折点跌落。第二次世界大战之后,日本经济的增长路径为验证理论提供了很好的案例。基于拓展模型的预测是,中国经济的转折点将在2-3年之内到来,之后经济增速将大幅度下降,进入略高于6%的中速增长阶段。未来中国的增长动力就是在全要素生产率上与发达国家的巨大落差。要将这种动力释放出来,就必须清除制约全要素生产率提高的因素,推动市场化方向的改革"再出发"。

It is not feasible to rely on the long-term stimulation of high investment growth to sustain economic growth, because the declining of capital profit rate will eventually lead to investors reluctant to invest. In an opening economy, many money will outflow to look for higher profit. The Solow model does not consider the effect of the capital outflow. In the extended model, the economic system is composed of two parts： one is a developed country that has achieved the balance of growth and with low savings rate; another is a developing country that be in the catching-up phase, with high savings rate. With the change of ＂the rate of output to capital＂, developing country＇ s advantage of capital profit rate will gradually disappear. The catching-up process can be divided into three stages： the first stage foreign capital inflow; the second stage domestic capital outflow; stage III balanced growth. The starting point of the second stage is a turning point of the per capita capital growth. The growth rate of per capita capital will drop precipitously in this point, that will cause the growth rate of per capita output to drop. After World War II, the Japanese economy growth path provides a good case to verify the theory. Based on the extended model, the turning point of China＇s economic growth rate will come in the 2~3 years, after that China＇s economic growth rate will be greatly reduced to a moderate slightly more than the 6 %. The driving force of China＇ s economy in the future is the huge gap with the developed countries in the total factor productivity. To release the force, we must promote market-oriented reform to clear the restricting factors of total factor productivity.