Concentration measures When the market is splitted more evenly among more firms the concentration level is lower Assume there are n firms in an industry Use i as the index for firms.i=l..N qi is the output of firm i Q is the total output in this industry Firms percentage share in industry's output Si-100(qi/Q)
Concentration Measures • When the market is splitted more evenly among more firms, the concentration level is lower. • Assume there are N firms in an industry. Use i as the index for firms, i=1,…, N. qi is the output of firm i. Q is the total output in this industry. • Firm’s percentage share in industry’s output = Si=100(qi/Q)
Concentration measures We can rank them from high to low s(1 is the ith highest share Two measures of concentration Four firm concentration ratio ∑ The herfindahl-Hirshman index HR
Concentration Measures • We can rank them from high to low. S(i) is the ith highest share. • Two measures of concentration – Four firm concentration ratio – The Herfindahl-Hirshman index
Example S(1)S(2)S(3)S(4)S(5)S(6)S(7)S(8)S(9)S(10)14IH 10 500 000 000 803850 20202020000 802000 3100/31003100/30 0 100 449490.250.250250.250.250.250.250259854802 The herfindah -Hirshman index contains more information and is more accurate. It is more frequently used
Example • The Herfindahl-Hirshman index contains more information and is more accurate. It is more frequently used
ergers The terms mergers, takeovers, acquisitions. and integration describe a situation where independently owned firms Join under the same ownership We will use the term merger to refer to any type of joining ownership and disregard the question of whether the merger is initiated by both firms, or whether one firm was taken over by another. Instead we investigate the gains and incentives to merge and the consequences of mergers for the subsequent performance and productivity of the firms involved for consumers' welfare. and for social welfare
Mergers • The terms mergers, takeovers, acquisitions, and integration describe a situation where independently owned firms join under the same ownership. • We will use the term merger to refer to any type of joining ownership and disregard the question of whether the merger is initiated by both firms, or whether one firm was taken over by another. Instead, we investigate the gains and incentives to merge and the consequences of mergers for the subsequent performance and productivity of the firms involved, for consumers' welfare, and for social welfare
Types of mergers Horizontal merger between two competitors Goods are substitutes Vertical merger between a firm producing an intermediate good (or a factor of production) and a firm producing the final good that uses this intermediate good Conglomerate: merger between firms producing less related products
Types of Mergers • Horizontal: merger between two competitors: Goods are substitutes. • Vertical: merger between a firm producing an intermediate good (or a factor of production) and a firm producing the final good that uses this intermediate good. • Conglomerate: merger between firms producing less related products