Sure, the stock-to-flow ratio is a measure used to evaluate the scarcity of a particular resource. It is calculated by dividing the total amount of the resource that is currently available (the stock) by the yearly production (the flow).

The higher the stock-to-flow ratio, the higher the scarcity of the resource. Gold has a higher stock-to-flow ratio than silver because gold is much rarer and more difficult to produce. This is why gold is considered a more valuable precious metal than silver.

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