A 2015 study showed that Mexico`s prosperity increased by 1.31% as a result of NAFTA tariff reductions and by 118% for Mexico`s intra-Bloc trade.  Inequality and poverty have decreased in the regions of Mexico most affected by globalization.  Studies from 2013 and 2015 showed that Mexican small farmers benefited more from NAFTA than large farmers.   Nevertheless, the “Most Favored Nation” (MFN) clause played an important role in NAFTA. Under NAFTA, all co-signed countries are granted MFN status, which means that they have to treat all parties on a single level in terms of trade. Thanks to the MFN, countries are not allowed to favour investors from non-NAFTA countries or to show greater favours towards foreign investors. In fact, they all have to be treated the same in the agreement. U.S. President Donald Trump, angered by Canada`s “nearly 300 per cent” milk tax, has threatened to leave NAFTA Canada.  Since 1972, Canada has been working to establish a supply management system that is under pressure from the United States, with a focus on the dairy industry. But that has not yet been done, as Quebec, which owns about half of the country`s dairy farms, continues to support supply management.  Chapter 19 of NAFTA was a trade litigation mechanism that subjects anti-dumping rules and countervailing law (AD/CVD) rules to international panel review or conventional judicial review.
 In the United States, for example, review of decisions by authorities imposing anti-dumping and countervailing duties is generally referred to the U.S. International Court of Commerce, a Section III court. However, the NAFTA parties were given the opportunity to appeal decisions against binational bodies made up of five citizens of the two NAFTA countries.  Participants were generally lawyers with experience in international commercial law. Since NAFTA did not contain physical provisions for AD/CVD, the panel was tasked with determining whether the final decisions of the agencies to which AD/CVD were parties were consistent with domestic national law. Chapter 19 was an anomaly in international dispute resolution because it did not apply international law, but required a body made up of individuals from many countries to review the application of a country`s domestic law. [Citation required] Although President Donald Trump warned Canada on September 1 that he would exclude them from a new trade deal if Canada did not comply with its demands, it is not clear that the Trump administration has the power to do so without congressional approval. :34-6 According to reports by the Congressional Research Service (CRS), one was published in 2017 and another on July 26, 2018, it is likely that President Trump would need congressional approval for fundamental changes to NAFTA before the changes are implemented. :34-6 In 1992, President Bush (USA), Prime Minister Brian Mulroney (Canada) and President Salinas (Mexico) signed the North American Free Trade Agreement. The parties also signed two complementary agreements on labour and environmental protection. The three countries ratified the convention in 1993 and came into force on 1 January 1994. According to the Sierra Club, NAFTA has contributed to large-scale export-oriented agriculture, resulting in increased use of fossil fuels, pesticides and GMOs.
 NAFTA has also contributed to environmentally harmful mining practices in Mexico.  It has prevented Canada from effectively regulating its oil sands industry and has created new legal opportunities for transnational companies to combat environmental legislation.  In some cases, environmental policy has been neglected as a result of trade liberalization; In other cases, NAFTA`s investment protection measures, such as Chapter 11, and measures to address non-tariff barriers