税收、收入不平等和内生经济增长

企业家(通过金融中介)从家庭借贷来支撑创新。二者在企业家的努力不为外人所见的情形下双方签订信用合同分享创新带来的垄断利润(即蛋糕)。两个有代表性经济人(企业家和家庭)的存在允许人们在内生经济增长模型里研究收入不平等。本文研究发现,企业家分配份额的增加一开始会提升增长速度,但是过了一定值后会拉低增长速度;而该份额的增加一直拉大企业家和工人间的收入差距。所以降低企业家获得的蛋糕的份额的分配改革可缩小收入差距。提高企业家来自创新的收入的税率将降低他们的努力程度,从而降低增长速度,但是该税率的提高有助于降低收入不平等程度。存款收入的税率提高尽管不会改变企业家的努力程度,但是也会降低经济增长速度,而且不会降低收入不平等(如果工人有一定比例的存款)。对于劳动收入(工人工资)的税率增加会加剧工人和企业家间的收入不平等,但对经济增长速度没有影响。

Taxation,Income Inequality and Endogenous Growth

Entrepreneurs borrow from households via financial intermediaries to finance innovations. With entrepreneur’s effort unobservable to others, they sign credit contracts to share the monopolistic profit on innovations. The existence of two representative agents (an entrepreneur and a household) permits a study of income inequality between agents in new growth models. We find the following. First, an increase in entrepreneur’s share raises economic growth initially, but beyond a point, it will decrease growth, while such an increase always increases the income gap between entrepreneurs and workers. Second, an increase in the tax on the income of entrepreneurs from innovation would reduce their effort and thereby decrease the growth rate, while it would help to reduce income inequality. In contrast, an increase in the tax on the interest earnings decreases the growth rate, although it does not affect entrepreneur’s effort; such an increase, however, would not help to reduce income inequality. A tax on labor income (the wage) would increase income inequality, leaving the balanced growth rate unchanged.