Tariff bindings shape global trade agreements, paving the way for free trade.
Multilateral tariff binding liberalization affects the formation of Preferential Trade Agreements (PTAs). High bindings lead to Free Trade Agreement (FTA) expansion constraints due to free riding incentives, while low bindings lead to exclusion incentives. Initially, tariff binding liberalization results in Custom Union (CU) formation, hindering global free trade. However, further liberalization leads to FTA formation, promoting global free trade. This research sheds light on the debate between FTAs and CUs.