Media Briefings

The Impact Of Gurus On Wine Prices: Measuring The Robert Parker Effect On Young Clarets

  • Published Date: June 2008

Robert Parker is widely regarded as the most influential wine expert in the world,
particularly for his power over the prices of en primeur Bordeaux wines, those that
are still very young and not yet bottled. New economic research estimates the effect
of Parker oenological grades and finds that, had he published grades in 2003, the
average en primeur price would have been almost three euros higher per bottle.
Robert Parker’s wine reports and oenological grades exercise an enormous power
over wine prices, especially en primeur prices, which are established just six or
seven months after the harvest. The quality of such young wines is hard to judge,
which might explain why Parker has a relatively large influence on en primeur prices.
The research by Michael Visser and colleagues – published in the June 2008 issue
of The Economic Journal – exploits the fact that in 2003, the chateau owners had to
determine their prices without knowledge of the Parker grades, whereas in previous
years the grades were made public before prices were determined. This unusual
event makes it possible to estimate the effect of Parker grades.
Each spring (since 1994), Robert Parker comes to Bordeaux to evaluate a sample of
en primeur wines of the latest vintage. He publishes his findings in the journal The
Wine Advocate
, usually the April issue. The en primeur prices are fixed by the
chateau owners in the weeks and months thereafter, giving them the possibility to
incorporate the information contained in the Parker grades.
In 2003, things went differently because the wine expert did not come in the spring to
taste the most recent vintage (the 2002 vintage). It meant that the chateau owners
had to determine their prices without knowledge of the grades attributed by Parker.
The researchers use this is to estimate a Parker effect on en primeur prices. They
obtained the 2002 and 2003 en primeur prices for approximately 250 wines from a
large Bordeaux wine broker. These data were matched with data from The Wine
, making it possible to determine which of the wines were graded in 2002.
The Parker effect is simply defined as the mean price evolution (between 2002 and
2003) of the sub-sample of graded wines minus the mean price evolution of the
ungraded wines.
The researchers’ estimate of the overall Parker effect equals 2.80 euros per bottle
(which corresponds to 15% of the average en primeur price in 2003), and this
estimate is strongly significant.
The Parker effect increases with the ranking of the wine. Estimates by appellation
show that the Parker effect is the largest for wines from Pomerol, which is interesting
since these are precisely the wines that Robert Parker appreciates the most.
Notes for editors: ‘The Impact of Gurus: Parker Grades and En Primeur Wine
Prices’ by Hela Hadj Ali, Sebastien Lecocq and Michael Visser is published in the
June 2008 issue of the Economic Journal.
The authors are at INRA, 48 boulevard Jourdan, 75014 Paris.
For further information: contact Michael Visser on +33 1 43 13 63 68 (email:; or Romesh Vaitilingam on +44-7768-661095 (email: