The unproductive and productive labor is maintained by what a country produces. If a smaller proportion of labor is productive than unproductive then the productive capacity of a country will decline. Each year that there is more unproductive labor, as opposed to productive labor, the quantity that a country produces will decline. All revenue, no matter what industry, follows this basic pattern. The second can be used to maintain either productive or unproductive labor.
People only employ capital to obtain a profit.
Therefore the proportion between productive and unproductive labor depends upon the proportion of the annual produce is destined for replacing a capital and that which is revenue- either as rent or profit. The more money that is invested in capital the richer the country. The countries that are wealthier have more productive labor. The more that people invest in capital the more industrious the country is. The less capital investment the poorer and more idle the towns are.