Statutory depletion in excess of cost depletion is an example of a permanent difference.

Statutory depletion is a tax deduction that is based on a percentage of revenue generated from a natural resource property. It is a permanent difference because it is not reversed in future periods and is therefore not included in the calculation of deferred tax assets or liabilities. In contrast, cost depletion is a method of calculating depreciation that is based on the cost of acquiring the resource property, and it is a temporary difference because it will eventually reverse as the resource is depleted.