資本結構、財政政策、貨幣政策與經濟成長

CAPITAL STRUCTURE, FISCAL POLICY, MONETARY POLICY AND ECONOMIC GROWTH

本文建構一個具債權代理成本的內生經濟成長模型，藉由理論分析可以得到：（1）提高（降低）公司證券利息所得稅率將傷害（有益）長期就業與經濟成長、長期通貨膨脹惡化（改善）、資本財市場價格下挫（上揚），但對公司長期負債權益比的影響無法確定。（2）不論是公司利潤稅率、股利所得稅率或是股利率，其對總體經濟的影響是不確定，因為政策改變資本財價格，進而誘發的資本財稅後邊際產量的變化，扮演一個重要角色。（3）提高（降低）名目利率是否對長期就業、經濟成長、通貨膨脹愈有害（有益），取決於公司債券利息所得稅率是否高於（低於）公司利潤稅率；其中，貨幣政策對外部融資貼水的影響是關鍵。數值模擬結果發現：不論是緊縮財政政策、寬鬆股利政策或是單位債權代理成本的升高皆不利於就業、經濟成長和通貨膨脹率，但對公司資本結構的影響則各有不同。提高名目利率雖對就業和經濟成長有所助益，卻需要付出通貨膨脹率與負債權益比皆上揚的代價。貨幣政策下，負債權益比和經濟成長呈現順循環關係。

This paper develops an endogenous growth model with capital structure that incorporates agency costs in the bond market. The main results from the theory analysis are as follows: (1) Increasing the tax rate imposed on the corporate bond yield reduces economic growth, employment, the inflation rate and the market price of capital. However, the im-pact of it on the firm’s debt-to-equity is ambiguous. (2) The impact of the corporate tax, the dividend tax, and dividend yield on economic growth, employment, inflation rate, and the debt-to-equity is ambiguous. (3) A high nominal interest rate is associated with high economic growth, employment, debt-to-equity ratio and inflation rate if the corporate tax rate is higher than the tax rate on the corporate bond yield. The numerical results are summarized in the following. The tax on the corporate tax, the corporate bond yield, and the distributed dividend is harmful to economic growth, employment, and inflation rate. Similarly, an increase in dividend yield and agency cost is harmful to macroeconomic performances. But, the impact of those policies on debt-to-equity is different. The relationship between debt-to-equity and economic growth is procyclical for monetary policy.