in the New Statesman and Nation, he wrote an article entitled Proposal for a Tariff Revenue. He pointed out that the reduction of wages led to a reduction in national demand which constrained markets. Instead, he proposes the idea of an expansionary policy combined with a tariff system to neutralise the effects on the balance of trade. The application of customs tariffs seemed to him "unavoidable, whoever the Chancellor of the Exchequer might be". Thus, for Keynes, an economic recovery policy is only fully effective if the trade deficit is eliminated. He proposed a 15% tax on manufactured and semi-manufactured goods and 5% on certain foodstuffs and raw materials, with others needed for exports exempted (wool, cotton). In 1932, in an article entitled The Pro- and Anti-Tariffs, published in The Listener, he envisaged the protection of farmers and certain sectors such as the automobile and iron and steel industries, considering them indispensable to Britain. Critique of the theory of comparative advantage In the post-crisis situation of 1929, Keynes judged the assumptions of the free trade model unrealistic. He criticised, for example, the neoclassical assumption of wage adjustment. As early as 1930, in a note to the Economic Advisory Council, he doubted the intensity of the gain from specialisation in the case of manufactured goods. While participating in the MacMillan Committee, he admitted that he no longer "believed in a very high degree of national specialisation" and refused to "abandon any industry which is unable, for the moment, to survive". He also criticised the static dimension of the theory of comparative advantage, which, in his view, by fixing comparative advantages definitively, led in practice to a waste of national resources. In the Daily Mail of 13 March 1931, he called the assumption of perfect sectoral labour mobility "nonsense" since it states that a person made unemployed contributes to a reduction in the wage rate until he finds a job. But for Keynes, this change of job may involve costs (job search, training) and is not always possible. Generally speaking, for Keynes, the assumptions of full employment and automatic return to equilibrium discredit the theory of comparative advantage. In July 1933, he published an article in the New Statesman and Nation entitled National Self-Sufficiency, in which he criticised the argument of the specialisation of economies, which is the basis of free trade. He thus proposed the search for a certain degree of