Both gold-mining firms and oil-producing firms might choose to use futures to hedge uncertainty in future revenues due to price fluctuations. But trading activity sharply tails off for maturities beyond 1 year. Suppose a firm wishes to use available (short maturity) contracts to hedge commodity prices at a more distant horizon, say, 4 years from now. Do you think the hedge will be more effective for the oil- or the gold-producing firm?