The study found that the region's exports to markets in Mexico, the US and Canada have increased by 74% since the enactment of the North American Free Trade Agreement in 1993. Most of that increase comes from business-related ventures, says Bruce Wright, associate VP for economic development at the university. It's part trade, part tourism and business investments, he says.

While the increase paints a rosy picture, a close look at the numbers reveal that the Arizona-Sonora connection is losing ground to other border areas in terms of trade. The Arizona-Sonora region's share of the US-Mexican trade slipped to 3.9% in 1999, a drop from 5.6% in 1993, the study found.

Inattention to how well the region is doing in spurring trade between the two states as compared to other border regions is the cause for the slip, Wright says. The study runs counter to one from the Arizona Department of Commerce released earlier this year. It showed that Arizona is increasing its share of trade.