Beta The co-efficient which measures the degree of correlation between the returns on shares in a particular company and returns on the stock market as a whole. Common Costs Costs that are incurred in the supply of all or a group of services provided by the firm and cannot be directly attributed to any one service.
Common costs arise from the existence of economies of scope.
An accounting methodology, where assets are valued and depreciated according to their current replacement cost. The value of discounts from the standard tariff BT was offering at 31 July 1993, which BT must maintain in accordance with Condition 24C of its licence, or offer equivalent reductions in standard prices. Economic Rate of Return See Internal Rate of Return. Economies of Scale These are present where the unit cost falls as the level of output rises. Equal Proportionate Markups A method of recovering the common costs of interconnection, where the markup on the incremental cost of a network service is equal across all services.