Worries that the North American Free Trade Agreement might substantially increase Mexico-to-U.S. labor migration in the short run may be somewhat unfounded, according to an economic model developed by a University of California, Davis, agricultural economist. Computer simulations using a Mexican village economic model show that NAFTA will lead to only slightly more short-term migration, says J. Edward Taylor, a UC Davis agricultural economics associate professor who is presenting his findings at the American Association for the Advancement of Science meeting here this week. For the long-term, Taylor believes NAFTA should reduce Mexico-to-U.S. migration by creating new income opportunities in Mexico. Taylor's presentation will be at 2:30 p.m. Tuesday, Feb. 22, in the Monterey Room of the San Francisco Hilton & Towers. Had Congress rejected the NAFTA treaty last year, devaluation of the Mexican peso would have been imminent, and would have had a much larger effect in increasing migration, Taylor says. Taylor's computer modeling shows that Mexico-to-U.S. migration is much more sensitive to the exchange rate than to price fluctuations in corn, a heavily produced, staple item in Mexico's economy. For example, Taylor's research shows that a 10 percent devaluation of the exchange rate -- which would increase the value of dollar-denominated remittance checks in local currency -- would result in a 17 percent increase in migration. But a 10 percent decrease in the price of corn would increase migration only 2.6 percent, according to the computer model. These estimated increases in short-term migration are in addition to what is certain to be a very large base of migration into the United States in the 1990s, with or without NAFTA, Taylor says. NAFTA's effect on corn prices is actually anticipated to be a downward pressure of between 30 percent and 40 percent, but that effect is largely countered by NAFTA's positive, stabilizing effect on the international exchange rate, Taylor says. Overall, Taylor says, impacts of exchange rates on Mexican village economic activity and incomes are larger and more pervasive than the impacts of corn prices. And Taylor points out, corn prices in Mexico would have fallen over the next few years, with or without NAFTA, because Mexico's corn price support program had become too costly to maintain and plans were under way to phase out support prices more quickly than what NAFTA would require. Taylor's study is funded by the University of California Consortium on Mexico and the United States and the Stanford University North American Agricultural Policy Research Consortium.