This paper has been retracted and references to this paper in abstract, indexing, and citation databases should be deleted.

[Note (February 06, 2015)]
The article has been retracted as it (a major part of text and results) is a duplicate of the previously published article(s):

Alexander V. Prasolov, St. Petersburg State University St. Petersburg, Russia, download from here

This article has been retracted at the request of the Managing Editor.
The link to pdf file is active according to the COPE RETRACTION GUIDELINES
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[end note]
 

Retracted: February 06, 2015

AMS Subject Classification: 91B60, 91B64, 91B44, 91B02, 91B66

Key Words and Phrases: tariff policy, optimal tariffs, models of trade, trade policy

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