"There were classical liberals in Germany who opposed the interventionist excesses of the Erhard ministry and the Ordo School. The leaders of this laissez-faire group were Volkmar Muthesius and Hans Hellwig. But they could do no more than fight an honorable rear-guard action. Being denied professorships at the universities, their foremost means of action was Muthesius’s journal, to which Mises contributed several articles. Hellwig wrote to Mises:
""Men such as Erhard and maybe even more so Prof. Rüstow have strictly speaking not much to do with classical liberalism. Earlier classical liberals would have made no bones calling them social democrats. They would not have called them even social-liberals or socialists of the chair."
""I have no illusions about the true character of the politics and politicians of the “social market economy.” [Erhard’s teacher Franz Oppenheimer] taught more or less the New Frontier line of [President Kennedy’s] Harvard consultants (Schlesinger, Galbraith, etc.)"
"But because of the near total ignorance of foreign languages, Mises explained, the American public had a very unrealistic notion about what the German “social market” model stood for. The only issue of German politics included in the American debate was the monetary policy of the German central bank, which was much less inflationary than the policies of the US Federal Reserve. Thus the ruling class in Germany was perceived as devoted to classical-liberal principles such as sound money and international trade.
"Erhard’s success changed the Mont Pèlerin Society, sweeping in the very themes Mises had stressed should be excluded — such as the need for antitrust and the possible virtues of credit expansion. On both issues Mises sided with Volkmar Muthesius, who argued that the best way to combat monopolies was to abolish the policies and government institutions that created them in the first place. Mises was especially wary of yet another round of discussions of antitrust laws. In his youth he had witnessed the anticartel agitation that followed their rise in the 1890s. At the time, the debate had been propelled by the Verein für Socialpolitik, which was always seeking a new rationale for more interventionism. For decades now he had not come across new arguments on either side, and he expected that any debate in the Mont Pèlerin Society would quickly turn toward an interventionist agenda, rather than addressing the main case of present-day monopoly prices: the US price policies for agricultural products. It was probably due to his influence that the topic did not appear until the 1956 Mont Pèlerin Society meeting in Berlin, by which point many German professorial members had urged Hayek to set the monopoly question on the program. The issue could no longer be avoided."