Countervailing duty subsidy calculation measures investigation-period benefits using commercial benchmarks, allocation rules, and narrowly permitted deductions. Countervailing duty subsidy calculation measures the benefit received during the investigation period, adjusted by normal commercial interest rates and expressed per unit or, where appropriate, ad valorem. Grants, tax concessions, loans, guarantees, government goods or services, government purchases, equity capital, and debt forgiveness are valued against prescribed commercial or market benchmarks. Recurring subsidies are generally expensed in the investigation period, while qualifying non-recurring fixed-asset subsidies are allocated over the relevant depreciation period. Allocation uses export volume, total sales, or product-specific sales according to the subsidy benefit.