Illegal Immigration Varies Widely, Study Finds

Illegal immigration, often pictured as an inexorable stream of border-jumpers and visa-overstayers, is actually a fluctuating phenomenon that responds sharply to economic shifts and other factors.

That is the central finding of a new study by the Public Policy Institute of California, an independent, San Francisco-based research organization that focuses on population issues and other concerns.

In fact, the study’s author, Hans Johnson, found that the movement of illegal immigrants to California has varied widely in recent years--ranging from relatively low levels in the early 1980s to a doubling later in the decade, before subsiding again in the early 1990s. The shifting economies of Mexico and California have a lot to do with the variations, Johnson concluded.

“The changes in flows are quite dramatic over time,” said Johnson, who developed the estimates from a model based on U.S. Census findings, birth and death records, motor vehicle information, tax return data and other official figures.

The study period ended in 1993, before the collapse of the Mexican peso in December 1994 triggered what many believe is an ongoing surge in illegal immigration.

The new report adds to the growing body of research into illegal immigration, a contentious topic that has risen to the top of national policy debate. Demographers, social scientists and others are increasingly focusing on this semi-clandestine movement, an arena of study once largely confined to guesswork.

The study’s conclusions are in line with other less precise estimates, experts said. “The general pattern--a rise in the ‘80s followed by a fall in the early ‘90s--is consistent with all the evidence,” said Dowell Myers, a demographer and urban planner at USC.

According to U.S. Immigration and Naturalization estimates, more than 4 million illegal immigrants reside in the United States, about half of them in California. Of the total undocumented population, the INS says, about 50% arrived with valid visas, typically at airports, and the rest entered the country without valid documents, usually via the U.S.-Mexico border.

The influx has had a profound impact on the makeup of California’s population. It has contributed to a sharp rise in the proportion of Latino residents--Latinos make up a quarter of the state’s population--while compensating for a net decline in domestic migrants from other states. Between 1980 and 1993, the study found, illegal immigration accounted for 22% to 31% of the state’s population growth.

The new report is billed as the first to measure annual flows of illegal immigration. Earlier studies, such as an oft-quoted 1994 effort by the INS, usually lack year-to-year breakdowns.

Annual fluctuations are critical, experts agree, because changes enable policymakers and others to pinpoint so-called “push” and “pull” factors that drive the flow. While all acknowledge that economic opportunity is a key consideration, there is great dispute as to whether touted U.S. enforcement buildups--such as the current Operation Gatekeeper along the U.S.-Mexico border in San Diego--actually reduce the numbers by discouraging would-be crossers.

The study sheds no light on the effectiveness of Operation Gatekeeper, which was launched in 1994.

The report estimates that net annual illegal immigration surged from fewer than 100,000 in 1980 to more than 200,000 in the late 1980s, then dropped to about 125,000 a year in the early 1990s.

In analyzing his results, Johnson noted the strong correlation to economic conditions. California experienced brisk job growth in the mid-to-late 1980s, when the movement peaked, he said, while unlawful immigration ebbed in the early 1990s, as a recession gripped the state.

But Johnson also concluded that the more than doubling of illegal immigration levels during the late 1980s may well have been linked to another factor: The 1987-88 amnesty program that, he and others have postulated, may have sent many illegal immigrants heading north, hoping for a chance at a green card or seeking to be reunited with newly legalized family members. Ironically, congressional lawmakers who devised the amnesty program thought it would help reduce illegal immigration.

In formulating the estimates, the demographer devised a two-step research method: first estimating total annual changes in the California population during the 13-year period of review and then subtracting legal factors, such as lawful immigration and domestic migration from other states.