The Oddbins Good Grange Index is one of a number of indicative tools used by Oddbins to monitor the state of the market for Australia's most collectable wine, Penfolds Bin 95 Grange. By monitoring four recent but important vintages of Grange, we hope to gain an insight into the performance of not only these four important vintages but by association, the overall health of the entire Grange market. The assumption being that if the good Granges are doing well, so must the rest of the portfolio.
The four key vintages monitored are 1986, 90, 94 and 96, technically we should also be monitoring the famed 1971 vintage as well, but due to this wines general scarcity, we decided to leave it out of the index. In the future we also envisage that the 1998 vintage should also be included in the Index's calculation, but only when it's pricing settles down.
The index is achieved by Weighted Relative Price Index method (Yamane, Statistics: An Introductory Analysis, Harper & Row, 1969), a method very similar to but cruder than the ABS's Consumer price Index, that is a weighted average of realised prices.
We admit that it is a crude indication and it really should be used in conjunction with our published price guides and realised prices.