First, some Asian economies enjoy certain advantages by being party to both trading blocs. These so-called ‘overlapping members’ include four ASEAN members as well as Japan. For instance, their companies could enjoy TPP tariff preferences when selling to the US, and also from RCEP tariff preferences when buying parts and components from the PRC or India. As the tariffs are eliminated and business regulations are streamlined, the more real cost advantages there are for companies in global value chains. Moreover, if one agreement were to be derailed for some reason, the other could still be available. Asian countries thus benefit from being a party to both agreements. Open accession characterizes both agreements which open the door to more overlapping members. For the RCEP, any ASEAN FTA partner that was not a member of the initial negotiations can join later, provided it meets terms agreed with other participating economies.