Tasters’ bias in wine guides’ quality evaluations

Abstract

Using a new database on Italian wines rated by the Guida dei Vini di Veronelli from 2004 to 2009, we show that the tasters’ quality evaluations are affected by two sources of personal bias, namely generosity and personal preferences towards certain types of wine characteristics.

Keywords:

• asymmetric information
• quality
• ratings
• bias

JEL Classification:

• L15
• D82

Notes

¹ In order to control whether the parallel line assumption imposed by the ordered logitmodel is violated, we run a Brant test. As it often happens, the Brant test rejects the parallel lines assumption. Thus, we repeat the exercise by estimating with the partial proportional odds model the fourth specification of Table 2 (see Williams, 2006). Main results hold true, and are not shown for reasons of space but available upon request.

² The results are not shown but are available upon request.