Michael S. Teitelbaum (a demographer at the Alfred P. Sloan Foundation) and Philip L. Martin (professor of labor economics at the University of California at Davis) discuss "guest" worker schemes:

...Decades of experience with such temporary worker programs in high-wage liberal democracies worldwide show that neither the programs nor the migrants turned out to be genuinely "temporary."

Mexico is unlikely to realize sustained benefits from exporting workers. Migrants' payments sent back to relatives wane over time, and such payments can stimulate land price inflation, conspicuous consumption of imported goods, and rising inequalities of wealth rather than stay-at-home development.

In the past, proponents have declared that such migrants would require very little in public expenditures. Yet universally, some temporary workers find ways to bring their families to join them, and then become substantial beneficiaries of existing government-financed programs such as public education, healthcare, and safety-net services for low-income residents. Politicians have also discovered - too late - that temporary worker programs really are labor subsidies to low-wage sectors such as garments, labor-intensive agriculture, and in-home personal services, retarding efforts to raise the level of national wages and productivity.

Temporary-worker programs are often portrayed as a legal and humane alternative to unauthorized migration. But they fail to acknowledge that the last major Mexico-US temporary worker program, the so-called bracero program, actually was the initiator and accelerator of today's large-scale unauthorized migration. The same is true across Western Europe, where "guest worker" programs based on similar claims were embraced during the economic booms of 30 to 40 years ago. Their "guests" for temporary work were transformed into millions of permanently resident "foreigners," who today have very high rates of unemployment and welfare dependency...

By the same authors: "The Mirage of Mexican Guest Workers"