Ricardo's idea that in the long run the worker gets only a minimum wage came to be known as the iron law of wages. When the market price of labor rises above the national price a worker can healthy family. As population increases wages fall to their natural price or even below. When the market price of labor is below the natural price misery reduces the working population and wages rise. The long-run tendency is therefore for workers to receive the subsistence minimum. This pessimistic analysts was modified in two ways. First in an industrialized society with expanding capital the wages fund may rise faster than population and hence wages may remain above the subsistence wage for an indefinite period. Second Ricardo apparently did not view this natural wage as necessarily being a biologically substance wage in the same sense as did Malthus. Rather this wage depended on the habits and customs of the people and what they consider to be the minimum accepted subsistence.