Submitted on: 29 September 2016.
Revised on: 22 November 2016.
Accepted on: 20 December 2016.
___________________INTERNATIONAL ECONOMIC JOURNAL
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http://reply.papertrans.cn/2/129/12857/12857-33.png
Submitted on: 14 September 2012.
Revised on: 23 December 2012.
Accepted on: 07 January 2013.
___________________INTERNATIONAL ECONOMIC JOURNAL
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