… is from page 260 of Vol. 19 (Ideas, Persons, and Events  ) of The Collected Works of James M. Buchanan; specifically, it’s from Jim’s 1997 essay “Post-Socialist Political Economy” (emphasis added):
There will be general, although begrudging, acknowledgement that market organization is superior in the generation of economic value. But this attitude will have minor spillover effects on the socialized or transfer sectors of nonsocialist economies. A genuinely revolutionary establishment of the ideal structure of political economy as envisaged by the classical liberals will not take place. Individuals remain unwilling to jettison romanticized notions of collective control over economic processes.