发展经济学workshop   讲座时间：5月20日（星期三）下午2:00-3:30 讲座地点：国家发展研究院小教室 主讲人： 龚刚，南开大学   Understanding Business Cycles: Perspective from Stabilizing and Destabilizing Mechanism   Gang Gong and Yang Gao   We study economic fluctuation and business cycles from the perspective of stabilizing and destabilizing mechanism. While price adjustment can be regarded as a stabilizing mechanism, whether there exist other mechanisms to destabilize the economy? We find that as earlier as in 1939, Harrod had already proved the existence of destabilizating mechanism the firm's investment adjustment - by showing his knife-edge problem. For this, we construct a macro-dynamic model with investment and price as the core macroeconomic variables. The analysis shows that the interaction between the stabilizing mechanism (price adjustment) and the destabilizing mechanism (investment adjustment) generates fluctuation and cycles for the economy. Yet, due to the stickiness in its adjustment, the pricing as a stabilizating mechanism may not be sufficient for the economy to be stabilized. In this case, additional stabilizing from government policy may become necessary