From macroeconomic viewpoint, there are three important factors in an economy: national income, general price level, and employment. Although it is difficult to say which factor is the most important among them, there is no doubt that employment has a tremendous importance in the economy. Moreover, these factors are interdependent. Employment influences both general price level and national income. Ignoring the short term effect, the higher employment will result in a more stable general price level and more stable national income. Therefore, we can consider employment to be a very important factor of every economy.