NAFTA Seen as Aid to Cutting Drug Flow : Trade: Customs chief believes pact will foster cooperation between U.S. and Mexico. But a congressional report counters his outlook.

The North American Free Trade Agreement is expected to make it easier to intercept narcotics arriving in the United States from Mexico, the U.S. commissioner of customs said Monday.

Although cross-border commerce is likely to increase significantly, providing more opportunities to camouflage illegal drug shipments and other contraband, the three-way trade pact should improve interception efforts by fostering a climate of cooperation between the two countries, Customs Service chief George J. Weise said in an interview with The Times.

The Customs Service already is enlarging its staff in anticipation that the agreement will be approved, he said. Under congressional mandate, the agency is increasing its agents in the region by about 20%, from approximately 1,400 to 1,700.

Weise contended that the trade pact would enable Customs agents to enter Mexican plants that they now lack authority to inspect. While their access would be primarily to ensure that goods bound for the United States actually originate in Mexico, it also would give them the opportunity to look for signs of illicit narcotics.

But his upbeat assessment of the free trade agreement’s impact on the narcotics fight was countered by a congressional analysis issued Monday. The report found fault with many of the major studies that have looked at its potential impact on U.S. jobs, predicting that the agreement could cause major shifts in the domestic labor market and lead to lower wages for some workers.

If approved by simple majorities in the House and Senate, the pact would eliminate tariffs on trade among the United States, Mexico and Canada over 15 years. It would take effect Jan. 1.

Critics have argued that cheaper labor costs and lax enforcement of environmental regulations in Mexico will lead U.S. companies to move plants there. Supporters have maintained that other factors in Mexico, including poor transportation and utility facilities, will increase the cost of doing business there and that lowered tariffs on U.S. products will increase the market in Mexico for American-made goods.

The Administration has asserted that nearly all of some two dozen studies have forecast job gains, with officials most often predicting an increase of 200,000 jobs in two years. Ross Perot, the Texas billionaire and former independent presidential candidate, on the other hand, has said that the agreement could end up costing the United States 5.9 million jobs.

But the congressional study found that that the economic models on which many such studies have been based are seriously flawed for a variety of reasons. The congressional review was prepared for the Joint Economic Committee, whose chairman, Rep. David R. Obey (D-Wis.), strongly opposes the agreement.

“Too often, proponents and opponents on both sides of the debate have been overreaching when they use these studies,” the report said. Of the studies reviewed for Congress, 10 found a favorable or neutral outcome as a result of the agreement and six were negative.

The figure cited by Perot was “highly implausible,” while the flaws in other studies made them of limited use, the report said.

“Net job change as an outcome of NAFTA is likely to be much smaller than many proponents or opponents claim--perhaps up to 200,000 net jobs gained or lost over five years or more,” the report said. “But even if the United States turned out to be a marginal winner in net jobs, that does not mean that NAFTA could not have substantial negative impacts for a large number of Americans. In fact, NAFTA could result in gross job dislocations of 500,000 or more, and downward pressure on U.S. wages, especially for non-professional workers.”

In another development, Administration officials and congressional aides said they have nearly solved the problem of making up the revenue that will be lost when tariffs are eliminated. They said they are working on a plan to increase the tax charged to air and sea travelers entering the United States from Mexico, raising the figure from $5 to $6.50.

An original plan to double the $5 tax met with an outcry from the travel industry and from a group of Republican House members.

In remarks at a news conference Monday, Clinton highlighted the impact the agreement could have on narcotics interdiction and other situations, saying that it would mean “a much better climate of cooperation on drugs and immigration and a whole range of other issues with Mexico. It is a very, very important agreement.”