New evidence on using expert ratings to proxy for wine quality in climate change research

This paper provides new evidence on the validity of using expert ratings of wine as a measure of wine quality for predicting the effects of climate change on the wine industry. We used Bob Campbell’s ratings of New Zealand wines to look for a relationship between the ratings and climatic variables that predicts a plausible optimal growing-season temperature for the main wine varieties and wine regions in New Zealand. Such a relationship can be used to forecast the effects of climate change on wine quality to better understand when wineries need to adapt to a warming climate. We used both individual wine ratings and overall vintage ratings, averaged by region and variety from the individual ratings, to compare in a controlled setting their success in predicting plausible optimal temperatures. We find that using the vintage ratings produces substantially more precise and plausible findings than using the individual ratings. We conclude that there is great potential in using vintage data constructed from expert ratings for individual wines for climate change research.