The U.K. has started negotiations to join the Comprehensive and Progressive Agreement for Trans-Pacific Partnership (CPTPP) trade group which includes Japan, Canada, Mexico, Australia and seven other countries. Membership would certainly boost the U.K.’s post-Brexit free trade relations and would cover 8.2% of U.K. exports in the 12 months to June 30. Yet, the U.K. would be a rule-taker and may forego better terms if it pursued bilateral deals. Joining would also complicate the implementation of a new trade deal with Japan and would be hampered by Mexico and Canada’s membership of USMCA ...