its long period of increase. Reasons for the change include a rising share of older workers, an increase in school enrollment rates among young workers, and a decrease in female labor force participation. The labor force participation rate can decrease when the rate of growth of the population outweighs that of the employed and the unemployed together. The labor force participation rate is a key component in long-term economic growth, almost as important as productivity. A historic shift began around the end of the Great Recession as women began leaving the labor force in the United States and other developed countries. The female labor force participation rate in the United States has steadily decreased since 2009, and as of April 2015, the female labor force participation rate has gone back down to 1988 levels of 56.6%. Participation rates are defined as follows: The labor force participation rate explains how an increase in the unemployment rate can occur simultaneously with an increase in employment. If a large number of new workers enter the labor force but only a small fraction become employed, then the increase in the number of unemployed workers can outpace the growth in employment. Unemployment-to-population ratio The unemployment-to-population ratio calculates the share of unemployed for the whole population. This is in contrast to the unemployment rate, which calculates the percentage of unemployed persons in relation to the active population. Particularly, many young people between 15 and 24 are studying full-time and so are neither working nor looking for a job. That means that they are not part of the labor force, which is used as the denominator when the unemployment rate is calculated. The youth unemployment ratios in the European Union range from 5.2 (Austria) to 20.6 percent (Spain). They are considerably lower than the standard youth unemployment rates, ranging from 7.9 (Germany) to 57.9 percent (Greece). Effects High and the persistent unemployment, in which economic inequality increases, has a negative effect on subsequent long-run economic growth. Unemployment can harm growth because it is a waste of resources; generates redistributive pressures and subsequent distortions; drives people to poverty; constrains liquidity limiting labor mobility; and erodes self-esteem promoting social dislocation, unrest, and conflict. The 2013 winner of the Nobel Prize in Economics, Robert J. Shiller, said that rising inequality in the United States and elsewhere is the most important problem. Costs Individual Unemployed individuals are unable to earn money