These prices for labor are in turn influenced by the demand for the products and services for which workers are hired. As a result, wages in different occupations rise and fall over time in large part because of changes in the prices for those consumer goods and services. For example, as automobiles replaced horses in the first part of the 20th century, the wages of blacksmiths and saddlemakers fell sharply, while the wages for auto mechanics rose. Similarly, in just the past few years, the demand for workers with college degrees has increased sharply in most market economies, largely because most businesses now work with more sophisticated technologies than they have in the past. Robert is attracted to computers, in part, because he sees it as a growing field with relatively high demand and, consequently, high wages.
International trade can also be an important factor in determining overall demand.
Workers who prepare for careers that experience strong growth in demand will gain from their foresight. Those who try to cling to jobs in declining markets using traditional skills will often be disappointed, and may even find themselves unemployed. They will need training, whether provided through their own resources, by government, or by their employer. This constant emphasis on producing what consumers want is, over time, the most fundamental reason why labor and other resources are so productive in market economies.