Commodity prices can predict changes in consumer prices in G-7 countries. While commodity prices often change before consumer prices, they are not always directly linked in the long run. Including commodity prices in inflation forecasts can improve accuracy, but the results may not be consistent over time. Different ways of weighting commodity prices in an index can help track inflation trends, but they may not always outperform traditional methods. Overall, changes in commodity prices tend to signal upcoming changes in consumer prices for major industrial countries.