In 2004, Scott Baier and Jeffrey Bergstrand published that there were three key economic determinants for the formation of PTA. Countries are more likely to participate in ATPs when they have lower transportation costs and larger economies. Third, countries of similar economic size should benefit the most from PTA training. Economic determinants such as GDP, similarity in economic size and distance between countries rightly predict more than 80% of the PTA from 2020.  Most of the reciprocal agreements covered by the instrument are free trade agreements. Free trade agreements (FTAs) remove barriers to trade between members and provide preferential access to markets on a reciprocal basis. In addition to trade in goods, free trade agreements generally cover trade in services and investment rules and remove tariff and non-tariff barriers. They may also include a number of provisions relating to customs cooperation and trade facilities, as well as harmonising standards and promoting regulatory cooperation in various areas. 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.  In principle, we can distinguish between unilateral trade agreements and systems (proposed from one party to the other) and reciprocal trading systems (negotiated and agreed upon by both parties). 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 obviously not a physical place (see explanation above). An essential difference between a free trade agreement and an EPA: while the PTA has a positive list of products for which tariffs must be reduced; In a free trade agreement, there is a list of nega-tives that does not reduce tariffs. Thus, free trade agreements are generally more ambitious in terms of registering posts for which tariffs must be reduced compared to an EPA. The Free Trade Agreement (FTA) is an agreement between two or more countries under which they agree to reduce/remove tariffs and non-tariff barriers to significant trade between them. The agreement can also cover services, investments, economic cooperation, etc.
The exact nature and extent of preferential treatment (i.e. more favourable terms of sale) differs in free trade agreements. A free trade area is a territory within a country or state where free trade rules apply (usually, but depending on the country and circumstances). These areas are mainly for importing and exporting goods and are suitable for a country that imports an input product and produces another product, reducing tariffs for producers. All of the above agreements are free trade agreements, but for a variety of reasons, members prefer to name them under another name.