The overwork of the employed part of the working class swells the ranks of the reserve, whilst conversely the greater pressure that the latter by its competition exerts on the former, forces these to submit to overwork and to subjugation under the dictates of capital. The condemnation of one part of the working class to enforced idleness by the overwork of the other part, and the converse, becomes a means of enriching the individual capitalists, and accelerates at the same time the production of the industrial reserve army on a scale corresponding with the advance of social accumulation.

 — Marx, Capital

Nearly three years since the ostensible end of the recession, the United States is still beset by over 15 percent underemployment — millions of Americans who would like to work full time and either can’t find jobs, or can only find part time work. We know from a large body of research that unemployment and underemployment have many negative consequences, not only financial but physical and mental. But this plague of underemployment exists alongside the corresponding problem of over-employment.

Our pre-eminent scholar of overemployment is the criminally obscure labor economist Lonnie Golden. In the broadest definition, overemployment happens whenever people are working longer hours than they say they would prefer. In a paper from a few years back, Golden gives a narrower definition: “workers’ inability to obtain reduced hours despite a willingness to proportionately sacrifice income.”