A new study on immigration policy finds that comprehensive immigration reform, as opposed to a guest worker program, would provide more economic benefit to the U.S. economy.

The study, by University of California economist Raul Hinojosal, was published on the Web site of the Immigration Policy Center, an organization in favor of comprehensive immigration reform.

The Agriculture Coalition for Immigration Reform supported the findings and is scheduled to participate in a congressional briefing about the study.

The coalition said fruit and vegetable producers have been losing market share to imported product as they face uncertainty over U.S. immigration policy.

Nearly a third of fresh fruit and a fifth of fresh vegetables consumed in the U.S. are imported, more than double of that in 1990. Meanwhile, the group said 77% of Texas fruit and vegetable producers reported scaling back their operations because of labor instability.

In the executive summary, the report said that “enforcement only” measures have failed to stem the tide of unauthorized immigration from Mexico and placed downward pressure on wages.

“Comprehensive immigration reform that legalizes currently unauthorized immigrants and creates flexible legal limits on future immigration in the context of full labor rights would help American workers and the U.S. economy,” according to the report.

Using statistics after the 1986 Immigration Reform and Control Act, the study estimates that comprehensive immigration reform would yield at least $1.5 trillion in additional U.S. gross domestic product over 10 years and boost wages for native-born and newly legalized immigrant workers.

On the other hand, the study found reliance on a temporary worker program alone would yield $792 billion of additional GDP over 10 years, while reducing wages for native-born and newly legalized immigrant workers.

A policy of mass deportation would result in a decline of the U.S. gross domestic product by 1.46% annually, or $2.6 trillion lost over 10 years. The study found that wages would rise for less skilled U.S.-born workers but reduce wages for higher skilled U.S.-born workers and lead to widespread job loss.