It is F.A. Harper.

And Hayek's work had incalculable effect in converting or helping to convert many socialist intellectuals to the individualist, capitalist ranks. John Chamberlain, one of the leading Left writers and critics of the 1930s and author of the noted Farewell to Reform, found his conversion to conservative-individualism greatly accelerated by the book, and Chamberlain contributed the preface to the Road to Serfdom. F.A. Harper, a free-market professor of agricultural economics at Cornell, found his dedication to libertarian views redoubled. And Frank S. Meyer, one of the leading theoreticians of the Communist Party, member of its national committee and head of its Workers' School in Chicago, found disturbingly convincing Hayek's portrayal of the incompatibility of socialism and freedom.