During the next two decades, a number of academic economists studied the effects of a free trade agreement between the two countries. Several of them—Ronald Wonnacott and Paul Wonnacott, and Richard G. Harris and David Cox—concluded that Canadian real GDP would be significantly increased if both U.S. and Canadian tariffs and other trade barriers were removed and Canadian industry could consequently produce at larger, more efficient scale. Other economists on the free-trade side included John Whalley of the University of Western Ontario and Richard Lipsey of the C. D. Howe Institute.