The Boston Carmen's Union and the Metropolitan Transit Authority yesterday accepted John Dunlop, professor of Economics, as neutral arbitrator. The two groups are currently involved in a dispute over wages.

He will serve on a committee with representatives of the Union and the MTA to effect a settlement on pay and working conditions. He is the single impartial member of the mediation group.

Dunlop, also a member of the faculty of the Graduate School of Public Administration, has been on leave from the University during the past year.