5GOLAN E, KRISSOFF B, KUCHLER F. Traceability in the US food supply: economic theory and industry studies[ R]. Washington DC: Agricultural Economic Report 830,2004.
6WILLIAMSON O E. The economics institutes of captialism[ M ]. New York: Free press, 1985:78.
7HEINKEL R. Uncertain product quality: the market for lemons with an imperfect testing Technology [ J]. Bell Journal of Economics, 1981 ( 12 ) : 625-636.
8MACHO-STADLER I, JD PEREZ-CASTRILLO. An introduction to the economics of information: incentives and contracts [ M ]. New York: Oxford University Press,2001:67.
9Allen, F., 1984, "Reputation and Product Quality", Journal of Economics, 15, pp.311-327.
10Antlc, J. M., 1996, "Efficient Food Safety Regulation in the Food Manufacturing Sector", American Journal of Agrlcultural Econom- ics,8,12, pp.1242: 1247.