Submitted on: 30 December 1999.
Revised on: 19 January 2000.
Accepted on: 13 February 2000.
___________________Istanbul Iktisat Dergisi-Istanbul Journal of Economics
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Submitted on: 11 February 2019.
Revised on: 09 June 2019.
Accepted on: 31 July 2019.
___________________Istanbul Iktisat Dergisi-Istanbul Journal of Economics
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