Lawrence E. Harrison wrote a highly critical and culturally biased column {Outlook, July 8} on President Bush's proposal for creating a Western Hemisphere free-trade zone and his recent understanding with President Carlos Salinas on a possible U.S.-Mexico free-trade agreement.

Mr. Harrison reflects the kind of wrong-headed thinking and cultural ignorance and bias that have consistently plagued U.S. policy toward Mexico and Latin America.

President Bush is right on target with his proposal for a hemispheric free-trade zone, starting with the U.S.-Mexico free-trade agreement. While Europe has been building and expanding its common market and Japan has been accumulating a gigantic trade surplus, the United States and the rest of the Americas have been standing still and getting the short end of the trade stick with Europe and Japan. The proposed agreement with Mexico could lead to its becoming our largest trading partner by the year 2000 and is a crucial step toward the establishment of a hemispheric free-trade zone.

President Bush's hemispheric initiative will lead to an eventual American community common market, uniting all the Americas and ensuring that no other trading bloc uses unfair trading tactics against the United States or any other American nation.

Combining the human and natural resources, capital, technological and marketing know-how of the Americas would allow us to compete head-to-head with any trade bloc from East or West. Moreover, it would spur economic development and improve the standard of living throughout the hemisphere.

If co-production is made the centerpiece of the free-trade negotiations, North, Central and South America will be able to achieve the most efficient and competitive economic production anywhere in the world. In addition, co-production is the key to bridging the large economic development gap between North and South and maximizing their comparative advantages.

Mr. Harrison's assertion that Latin American economic integration has not succeeded because of "cultural obstacles" reflects his cultural bias. I wonder how Mr. Harrison would explain Spain's booming economy and highly successful integration into the European Common Market. Hispanic culture did not get in the way in that case and neither will it hinder the proposed hemispheric free-trade zone.

Mr. Harrison's assertion that a free-trade agreement will not discourage illegal immigration is another point in his cultural ignorance. The agreement, while not a panacea, will promote more economic opportunity for Mexicans to remain in Mexico, where family togetherness is a cherished cultural value. Mr. Harrison erroneously states that if President Salinas opens up the political system, "it is quite possible that he will be defeated by Cardenas in 1994." Mr. Harrison should know that the Mexican Constitution does not permit reelection. Mr. Harrison also shows how outdated his knowledge of Latin America is when he refers to the Latin American Free Trade Association, which was succeeded by the Latin American Integration Association several years ago.

It is nobler to develop creative solutions than criticize like Mr. Harrison. President Bush and President Salinas are making their best efforts to deal with the economic problems and to realize the very significant potential opportunities that the United States, Mexico and the rest of the hemisphere can realize through free trade. The two presidents should be commended for their vision and political courage. ABELARDO L. VALDEZ Washington

The writer was assistant AID administrator for Latin America and the Caribbean during the Carter administration.