MACRINA and Zenaido Lopez wait stoically beside the stench of the fouled Rio Grande. When night falls, the two will join the age-old "immigration parade" across the border.
"The salary is tiny but it's much more than I can make on this side," says Mrs. Lopez of her former job in a laundry room of a country club outside Chicago. After a three-month visit with family in Guerrero, the couple are returning illegally to the United States to look for work.
At home and in the US, President Carlos Salinas de Gortari bills the North American Free Trade Agreement (NAFTA) as a means of creating good-paying jobs for the Lopezs and other "illegals" so Mexico can export products, not people.
It is a message that plays well in US-Mexico border states suffering unemployment in an election year. But many experts question whether NAFTA will reduce migrant flows to El Norte.
"NAFTA itself won't make an immediate difference in the migrant problem, indeed it may not make any difference at all," says Jeffrey Schott, a researcher at the Institute for International Economics in Washington D.C., who is a co-author of a recent study on the economic impact of NAFTA.
The belief that NAFTA will curb migration flows is based on the assumption that a free-market Mexican economy will attract investment and create new jobs, thereby closing the 8-to-1 wage gap between the average Mexican and US paycheck.
But Mr. Schott estimates that even a 30 to 40 percent narrowing of the income gap could take a generation to achieve. "And that would be a large increase for just one generation," he notes.
Much could depend on the kinds of investment the NAFTA agreement attracts to Mexico, says Leo Chavez, who studies California migrant groups at the University of California in Irvine.
"It will depend on whether you're creating more maquiladora jobs, the revolving-door jobs which attract mostly women, or longer-term jobs with some opportunity for upward mobility, such as the auto plants offer in parts of Mexico," Mr. Chavez says.
RESEARCH is scarce on US-Mexican migration flows and how economic changes affect these flows. But history seems to show a poor correlation. For example, Mexico had one of the strongest economies in the world, growing at an average annual rate of 6.3 percent from 1945 to 1980. Yet, despite its economic strength, Chavez notes, "you still had large scale migration."
Conversely, during Mexico's worst economic crisis of the 1980s, political scientist Manuel Garcia y Griego notes, migration to the US over a five-year period did not increase much more than 15 percent. "There are no concrete indications macro-economic changes have a significant change on migration. I think the idea that NAFTA will make a real difference is oversold," Mr. Garcia y Griego says.
Chavez and Garcia y Griego say that the US demand for cheap labor is more important than what is happening in the Mexican economy. "Assuming NAFTA reduces Mexican migration, California agriculture will still need laborers and we will still have hotels, restaurants, and copy centers which need low-wage workers."
Jorge Bustamante, director of the Colegio de la Frontera Norte, a leading Mexican research institution, tends to support the theory that migration is stimulated more by the US pull than by the Mexican push. For example, he notes migration flows may be climbing now despite a strong Mexican economy (3 to 4 percent growth) during the last three years when the US was experiencing weak or negative growth.
"US recessions create demand for undocumented workers," Dr. Bustamante says. "Small companies that would not ordinarily hire Mexican workers do, because it is the difference between failure and staying in business."
But longer term, Bustamante says Mexico's economic prosperity will prompt a drop in migrant flows.
A forthcoming study by the Colegio de la Frontera Norte, predicts that migration flows will fall by 40 percent if the Mexican economy grows at twice the population growth rate (2.1 percent) for the next 20 years. With NAFTA, the reduction "won't be any more than 10 percent greater," Bustamante says.
Sidney Weintraub, a Mexico expert at the University of Texas, Austin, agrees NAFTA will have a minor impact on immigration. More significant are the structural changes within the Mexican economy, he says. He predicts that "if Mexico grows at 5 to 6 percent over the next 10 to 15 years, we would see profound changes in immigration flows." But he adds: "That's assuming the income is distributed better than in the past."
Critics of the Salinas economic reforms say the growing gap between rich and poor makes that a significant caveat. Professor Weintraub says that poor distribution of income in Mexico's boom years between 1945 and 1980 may be why emigration remained relatively unchanged.