The Relation Between Firm Growth and Q with Multiple Capital Goods: Theory and Evidence from Panel Data on Japanese Firms
从多资本品投资模型推导出资本总量增长率与股票市场Q的一一对应关系，并用日本制造业企业面板数据估计该关系，发现早期现金流有额外解释力，后期在重工业中消失，调整成本低于调整后毛利润的一半。
We derive from a model of investment with multiple capital goods a one-to-one relation between the growth rate of the capital aggregate and the stock market-based Q. We estimate the growth-Q relation using a panel of Japanese manufacturing firms taking into account the endogeneity of Q. Identification is achieved by combining the theoretical structure of the Q model and an assumed serial correlation structure of the technology shock which is the error term in the growth-Q equation. For early years of our sample. cash flow has significant explanatory power over and above Q. The significance of cash flow disappears for more recent years for the heavy industry when Japanese capital markets was liberalized. The estimated Q coefficient implies that the adjustment cost is less than a half of gross profits net of the adjustment cost.