positions commensurate with their skills for extended lengths of time following layoffs. Skilled machinists who are laid off may find that they cannot find another job as a machinist and so they may work as a server in a restaurant, a job which does not use their professional skills. As the tertiary education of most students in Western countries is fully or partially subsidized by government monies (because it takes place at a state university or public university or because the student receives government loans or grants), the underemployment of recent college graduates may also be an ineffective use of public resources. Several solutions have been proposed to reduce skill-based underemployment: for example, government-imposed restrictions on public university enrollment in degree fields with a very low labor market demand (e.g. fine arts), or changes in degree cost model that reflect potential labour market demand. A related kind of underemployment refers to "involuntary part-time" workers, who could (and would like to) be working on a standard work-week (typically full-time employment means 40 hours per week in the United States) schedule but can find only part-time work. Underemployment is more prevalent during times of economic stagnation (during recessions or depressions). During the Great Depression of the 1930s, many of those who were employed were underemployed. Those kinds of underemployment arise because labor markets typically do not "clear" using wage adjustment. Instead, there is a non-wage rationing of jobs. Underuse of economic capacity Underemployment can also be used in regional planning to describe localities where economic activity rates are unusually low. This can be induced by a lack of job opportunities, training opportunities, or services such as childcare and public transportation. Such difficulties may lead residents to accept economic inactivity rather than register as unemployed or actively seek jobs because their prospects for regular employment appear so bleak. (These people are often called discouraged workers and are not counted officially as being "unemployed.") The tendency to get by without work (to exit the labor force, living off relatives, friends, personal savings, or non-recorded economic activities) can be aggravated if it is made difficult to obtain unemployment benefits. Relatedly, in macroeconomics, "underemployment" simply refers to excess unemployment, i.e., high unemployment relative to full employment or the natural rate of unemployment, also called the NAIRU. Thus, in Keynesian economics, reference is made to underemployment equilibrium. Economists calculate the cyclically-adjusted full employment unemployment rate, e.g. 4%