Since the beginning of the 20th century, several hundred bilateral THPs have been signed. The Canada Research Chair in International Political Economy`s TREND project lists approximately 700 trade agreements, the vast majority of which are bilateral.  A free trade agreement is a preferential regime in which members reduce tariffs on trade between them while maintaining their own tariffs on trade with non-members. There were also two regional trade agreements, the South Asia Free Trade Agreement (SAFTA, 2004) and the India-India Association of Southeast Asian Nations Agreement (ASEAN, 2010). Given the recent proliferation of bilateral TTPs and the emergence of mega-PTAs (broad regional trade agreements such as the Transatlantic Trade and Investment Partnership (TTIP) or the Trans-Pacific Partnership (TPP), a global trading system managed exclusively under the WTO now seems unrealistic and the interactions between trade systems must be taken into account. The increasing complexity of the international trading system resulting from the proliferation of EPZs should be taken into account when considering the choice of countries or regions used by countries or regions to promote their trade relations and environmental agendas.  ATPs have grown rapidly; In the 1990s, there were just over 100 PTAs. In 2014, there were more than 700.  A preferential trade zone (including preferential trade agreements, EPZ) is a trading bloc that offers preferential access to certain products from participating countries. This requires a reduction in tariffs, but not in their total abolition. A ZEP can be implemented through a trade pact. This is the first step in economic integration. The border between a EPZ and a Free Trade Area (EEA) can be blurred, as almost all ATPs have the main objective of becoming a free trade agreement in accordance with the General Agreement on Tariffs and Trade.
Preferential trade agreements (EPAs) or the Generalized Preference System (GSP) are a special status granted in trade by different countries. In the United States, the goal is to stimulate economic growth in developing countries, and the agreement provides duty-free access for up to 4,800 products from 129 designated countries and territories. The GSP was introduced on January 1, 1976 by the Trade Act of 1974, the U.S. government said. However, the Indian government believes that the plan has expanded since the creation of the World Trade Organization (WTO) in 1994. An EPI allows countries to trade with a small number of goods, making the volume minimal. Other PTAs can be attributed to political predictors. Countries under democratic rule are more likely to participate in PTAs than autocracy. Autocratic leaders are not elected and have therefore not threatened their power by disgruntled citizens.
Democratic leaders are encouraged to satisfy their constituents and PTAs can help drive down the price of consumer goods. Support for ATPs also allows democratic leaders to signal to voters that they are committed to a policy that improves their well-being. Countries are also more likely to join ATPs if competing countries have already done so.  The TTIP will, once completed, be a 27-member PTA between the United States and the European Community. The TPP comprises twelve member countries: Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore, the United States and Vietnam, as shown on the map below. The TPP will cover 40% of global GDP2 and 33% of world trade.