Fifth, all NAFTA countries were required to respect patents, trademarks and copyrights. At the same time, the agreement ensured that these intellectual property rights did not affect trade. The first agreement was the North American Agreement on Labour Cooperation (NAALC), which protected factory workers from possible job losses. The second agreement was the North American Agreement on Environmental Cooperation (NAAEC). The NAAEC was signed to address environmentalists` environmental concerns about the potential impact of rapid industrialization in Mexico due to a lack of experience in enforcing environmental regulations. After diplomatic negotiations in 1990, the leaders of the three nations signed the agreement on December 17, 1992 in their respective capitals.  The signed agreement then had to be ratified by the legislature or parliament of each country. Talks on a common trade area were launched in 1985 by Canadian Prime Minister Brian Mulroney with a proposal to formulate a free trade agreement between Canada and the United States. Negotiations began in 1986 and the two countries signed the agreement in 1988. The Agreement between Canada and the United States entered into force on January 1, 1989. Maquiladoras (Mexican assembly plants that collect imported components and produce goods for export) have become the symbol of trade in Mexico.
They moved from the United States to Mexico, hence the debate about losing American jobs. Revenues in the maquiladora sector had increased by 15.5% since the introduction of NAFTA in 1994.  Other sectors have also benefited from the free trade agreement, and the share of exports from non-border states to the United States has increased over the past five years, while the share of exports from border states has decreased. This allowed for rapid growth in borderless metropolitan areas such as Toluca, León and Puebla, all of which were sparsely populated as Tijuana, Ciudad Juárez and Reynosa. Clinton signed it on December 8, 1993; the Agreement entered into force on 1 January 1994.   At the signing ceremony, Clinton honored four people for their efforts to reach this historic trade deal: Vice President Al Gore, Council of Economic Advisers Laura Tyson, National Economic Council Director Robert Rubin, and Republican Congressman David Dreier.  Clinton also stated that „NAFTA means jobs. American jobs and well-paying American jobs. If I did not believe in it, I would not support this agreement.  NAFTA replaced the previous Free Trade Agreement between Canada and the United States. NAFTA has been complemented by two other regulations: the North American Agreement on Environmental Cooperation (NAAEC) and the North American Agreement on Labour Cooperation (NAALC). These tangential agreements were aimed at preventing companies from moving to other countries to take advantage of lower wages, softer health and safety regulations for workers, and more flexible environmental regulations.
This classification system offers more flexibility than the four-digit structure of the SIC by implementing a six-digit hierarchical coding system and dividing all economic activities into 20 industrial sectors. Five of these sectors are mainly those that produce goods, the other 15 sectors being exclusively those that provide some kind of service. .