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		| Kohei  Shiozawa | 
	
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		| ''Note on goodness-of-fit measures for the revealed preference test: The computational complexity of the minimum cost index'' | 
	
		| ( 2015, Vol. 35 No.4 ) | 
	
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		| The purpose of this paper is to show that computing the minimum cost index (MCI) for a given price-amount data set, proposed by Dean and Martin (2010, 2015) as a goodness-of-fit measure for the revealed preference test, is NP-hard. 
Our proof uses a polynomial reduction from the feedback arc set problem, which is a decision problem known to be NP-complete. 
Our result refines the NP-hardness result in Dean and Martin (2010), which is presented in a more abstract framework than our economic data setting. Thus the computation of MCI is NP-hard even if we restrict our attention to the revealed preference setting for economic data. 
We also discuss computational procedures for MCI and provide a way of approximating MCI in polynomial-time using approximation algorithms for the (weighted) feedback arc set problem. | 
	
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		| Keywords: Revealed preference,  goodness-of-fit measure,  minimum cost index,  NP-hard,  feedback arc set problem | 
	
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		| | Manuscript Received : Sep 29 2015 |  | Manuscript Accepted : Nov 21 2015 | 
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