1.4 Calculating Market Shares
1.41 General Approach
The Agency normally will calculate market shares for all firms (or plants) identified as market participants in Section 1.3 based on the total sales or capacity currently devoted to the relevant market together with that which likely would be devoted to the relevant market in response to a "small but significant and nontransitory" price increase. Market shares can be expressed either in dollar terms through measurement of sales, shipments, or production, or in physical terms through measurement of sales, shipments, production, capacity, or reserves.
Market shares will be calculated using the best indicator of firms' future competitive significance. Dollar sales or shipments generally will be used if firms are distinguished primarily by differentiation of their products. Unit sales generally will be used if firms are distinguished primarily on the basis of their relative advantages in serving different buyers or groups of buyers. Physical capacity or reserves generally will be used if it is these measures that most effectively distinguish firms.(15) Typically, annual data are used, but where individual sales are large and infrequent so that annual data may be unrepresentative, the Agency may measure market shares over a longer period of time.
In measuring a firm's market share, the Agency will not include its sales or capacity to the extent that the firm's capacity is committed or so profitably employed outside the relevant market that it would not be available to respond to an increase in price in the market.
1.42 Price Discrimination Markets
When markets are defined on the basis of price discrimination (Sections 1.12 and 1.22), the Agency will include only sales likely to be made into, or capacity likely to be used to supply, the relevant market in response to a "small but significant and nontransitory" price increase.
1.43 Special Factors Affecting Foreign Firms
Market shares will be assigned to foreign competitors in the same way in which they are assigned to domestic competitors. However, if exchange rates fluctuate significantly, so that comparable dollar calculations on an annual basis may be unrepresentative, the Agency may measure market shares over a period longer than one year.
If shipments from a particular country to the United States are subject to a quota, the market shares assigned to firms in that country will not exceed the amount of shipments by such firms allowed under the quota.(16) In the case of restraints that limit imports to some percentage of the total amount of the product sold in the United States (i.e., percentage quotas), a domestic price increase that reduced domestic consumption also would reduce the volume of imports into the United States. Accordingly, actual import sales and capacity data will be reduced for purposes of calculating market shares. Finally, a single market share may be assigned to a country or group of countries if firms in that country or group of countries act in coordination.
15 Where all firms have, on a forward-looking basis, an equal likelihood of securing sales, the Agency will assign firms equal shares.
16 The constraining effect of the quota on the importer's ability to expand sales is relevant to the evaluation of potential adverse competitive effects. See Section 2.