Although Lerner (1936) has derived an elegant symmetry theorem, this paper shows that he destroyed it subsequently. This paper also shows that Lerner is too ambitious in collecting taxation. His government may feel disappointed by the final result, for importers or exporters will react...

This paper unveils three dirty tricks exercised by Kemp and Shimomura (2000): 1. They play around with an ambiguous trade balance equation; 2. They change the convex social indifference curve into a concave one; 3. They think they can dictate market prices. Without these tricks, there is no...

This paper reviews the optimal tariff theory of Kahn (1947) and Graaff (1949), and finds that their solutions are not optimal. Indeed, their policy recommendations are welfare detrimental. Graaff's tariff is even uncertain, can be positive or negative

This paper changes the current view of tariff. It advocates taxing the exporters, rather than the importers. The new theory is based on the symmetry theorem developed earlier by Lerner. Taxing the exporters has all the same effects as taxing the importers with tariff, except that the former...

This paper points out some mistakes in the so-called optimal tariff theory. When they are corrected, the trade model does not offer any welfare implication. It removes a major blocking stone for the World Trade Organization to promote free trade

This paper unveils a serious mistake committed by Kemp (1967). His positive tariff is actually an export subsidy. The corrected Kemp model implies that the whole optimal tariff theory must have been working in the wrong direction

This paper unveils the tricks of how Kahn achieves his optimal tariff theory. When corrected, the optimal tariff turns out to be zero or negative.Apart from David Ricardo's comparative advantage, the most influential theory in the international trade study must be the optimal tariff theory (C....

This paper brings the price measurement into the offer curve space. It revitalizes absolute prices from relative price. It then splits the impact of depreciation into two stages, to prove that it is more damaging than import tariff