濱田弘潤 : 多角化企業の利潤分析 77 多角化企業の利潤分析 多角化ディスカウントの寡占理論による説明 * 濱田弘潤 (diversification discount) Keywords: JEL classifications: D43, L13, L22, G34 950-2181 2 8050 Tel. and fax: 025-262-6538 E-mail: khamada@econ.niigata-u.ac.jp
78 新潟大学経済論集第 85 号 2008- 英 1 ICT (diversification) (diversification discount) (conglomerate discount) (conglomerate) (influence activity)
濱田弘潤 : 多角化企業の利潤分析 79 2 3 4 5 6 2 2000 5 M&A 1 3 M&A 1960 M&A 1980 M&A 1930 M&A M&A 1980 M&A 1990 IT M&A 2 3 Besanko, Dranove, and Shanley (2003) 6 1. 2. (synergy) 3. 1. 2. 3. 4 (influence activity) (influence) (influence cost) Meyer, Milgrom, and Roberts (1992), Rajan, Servaes, and Zingales (2000), Scharfstein and Stein (2000) Scharfstein and Stein (2000) 1 Besanko, Dranove, and Shanley (2003) 1 1883 1900 M&A 2 1 1920 M&A 3 1960 M&A 4 1980 M&A 5 1990 M&A (1997) 2 M&A (2007) 3 IT 2005 2 10 TBS 4 (2005) 5 pp.201 215 3
80 新潟大学経済論集第 85 号 2008- 英 Milgrom and Roberts (1990) 5 Matsusaka (1993) 1960 Montgomery and Wernerfelt (1988) Lang and Stulz (1994) q (Tobin s q) q 10% Berger and Ofek (1995) (stand-alone value) 80 90 13% 15% Shin and Stulz (1998) Lins and Servaes (1999) 92 94 3 3 10% 15% Scharfstein and Stein (2000) Scharfstein (1998) q (demerger) Comment and Jarrell (1995) Berger and Ofek (1996) (takeover) 5 (2005) 5 Besanko, Dranove, and Shanley (2003) 6
濱田弘潤 : 多角化企業の利潤分析 81 Roberts (2004) 6 Chevalier (2002) 90 Villalonga (2002, 2004) 90 Villalonga (2002) 90 90 Campa and Kedia (2002) Roberts (2004) 90 3 Roberts (2004) 5 (pp.225-226) 7 (stand-alone firm) 6 Roberts (2004), Ch.5, pp.226 227 (2005) 5 pp.212 213 7 (2005) pp.211 212
82 新潟大学経済論集第 85 号 2008- 英 Roberts (2004) Villalonga (2002, 2004) 4 4 2 A B x = {A, B} x = {A, B} x x n x ( 1) 1 A n A B n B A i = {1, 2,...,n A } B j = {1, 2,...,n B } 1 (identical) x x (passive player) 2 (notations) A i B j
濱田弘潤 : 多角化企業の利潤分析 83 q i ( 0) q j ( 0) q A q B A 1 B 1 A B n A ( 1) n B ( 1) n n A + n B ( 2) Q A Q B U(Q A,Q B ) (Q A,Q B ) U(Q A,Q B ) > 0 U(Q A,Q B ) > 0 2 U(Q A,Q B ) < 0, 2 U(Q A,Q B ) < 0, Q 2 A Q 2 B 2 U(Q A,Q B ) < 0 A B p A p B U(Q A,Q B ) p A (Q A,Q B ) U(Q A,Q B ) p B (Q A,Q B ) p A(Q A,Q B ) = 2 U(Q A,Q B ) < 0, p B(Q A,Q B ) Q 2 Q A B = < 0, p A(Q A,Q B ) = p B(Q A,Q B ) = 2 U(Q A,Q B ) < 0 2 U(Q A,Q B ) Q 2 B (Q A,Q B ) ( p A(Q A,Q B ) )( p B(Q A,Q B ) ) > ( p A(Q A,Q B ) ) 2 p A(Q A,Q B ) < p A(Q A,Q B ) < 0 p B(Q A,Q B ) < p B(Q A,Q B ) < 0 A B c A ( 0) c B ( 0) p A (0, 0) >c A, p B (0, 0) >c B A B i j π i π j π A π B π A (p A (Q A,Q B ) c A )q A, π B (p B (Q A,Q B ) c B )q B A B Π A (Q A,Q B )=(p A (Q A,Q B ) c A )Q A Π B (Q A,Q B )= (p B (Q A,Q B ) c B )Q B PS(Q A,Q B ) Π A (Q A,Q B )+Π B (Q A,Q B ) CS(Q A,Q B ) U(Q A,Q B ) p A (Q A,Q B )Q A p B (Q A,Q B )Q B W (Q A,Q B ) CS(Q A,Q B )+PS(Q A,Q B )=U(Q A,Q B ) c A Q A c B Q B (subgame-perfect equilibrium) 2 x 2 A B q i q j (q ma,q mb )
84 新潟大学経済論集第 85 号 2008- 英 5 5 2 A B (n A 1) (n B 1) max π m(q ma,q mb ; Q ma,q mb ) π ma + π mb (1) (q ma,q mb ) =(p A c A )q ma +(p B c B )q mb =(p A (q ma + Q ma ; q mb + Q mb ) c A )q ma +(p B (q ma + Q ma ; q mb + Q mb ) c B )q mb Q ma n A 1 i=1 q i = Q A q ma, Q mb n B 1 j=1 q j = Q B q mb (1) 1 8 π m (q ma,q mb ; Q ma,q mb ) q ma π m (q ma,q mb ; Q ma,q mb ) q mb = p A c A + p A q ma + p B q mb =0, (2) = p B c B + p B q mb + p A q ma =0. (3) 2 2 π m qma 2 =2 p A 2 π m qmb 2 =2 p B 2 π m q ma q mb = p A + p B + + 2 p A Q 2 A + 2 p B Q 2 B 2 p A q ma + 2 π m qma 2 2 π m qmb 2 q ma + 2 p B Q 2 q mb < 0. (4) A q mb + 2 p A Q 2 q ma < 0. (5) B 2 p B q mb (< 0). (6) 2 π m ( ) 2 > 0. q ma q mb (7) A B π i π j max π i (q i,q i ; Q B )=(p A (q i + Q i,q B ) c A )q i q i and (8) max π j (q j,q j ; Q A )=(p B (q j + Q j,q A ) c B )q j q j (9) Q i n A 1 k=1,k i q k + q ma, Q j n B 1 l=1,l j q l + q mb 8
濱田弘潤 : 多角化企業の利潤分析 85 A B i j (8) (9) 1 π i (q i,q i ; Q B ) q i π j (q j,q j ; Q A ) q j = p A c A + p A q i =0, (10) = p B c B + p B q j =0. (11) A B q i = q A i q j = q B j 1 (10) (11) q A q B p A c A + p A q A =0, (12) p B c B + p B q B =0. (13) 1 (2), (3), (12), (13) (Cournot-Nash equilibrium) (qa,q B ;(q ma,q mb )) x AA p A (qa,q B ;(q ma,q mb ))=(q A,q B ;(q ma,q mb )) (14) x AB p A (qa,q B ;(q ma,q mb ))=(q A,q B ;(q ma,q mb )) (15) x BA p B (qa,q B ;(q ma,q mb ))=(q A,q B ;(q ma,q mb )) = x AB (16) x BB p B (qa,q B ;(q ma,q mb ))=(q A,q B ;(q ma,q mb )) (17) x AA <x AB < 0, x BB <x AB < 0, x AA x BB > (x AB ) 2 (14) (17) 1 (2), (3), (12), (13) p A c A + x AA q ma + x AB q mb =0, (18) p B c B + x BB q mb + x AB q ma =0, (19) p A c A + x AA q A =0, (20) p B c B + x BB q B =0. (21) (20) (21) p A c A = x AA q A p B c B = x BB q B A B π A π B A B π ma π mb π m (20) (21)
86 新潟大学経済論集第 85 号 2008- 英 π A =(p A c A )q A = x AA qa 2, (22) π B =(p B c B )q B = x BB qb, 2 (23) π ma =(p A c A )q ma = x AA q A q ma, (24) π mb =(p B c B )q mb = x BB q B q mb, (25) π m = π ma + π mb = x AA q A q ma x BB q B q mb. (26) 1 2 x AB q A x BB q B = x AAx BB x 2 AB x AA q mb > 0, x AB q B x AA q A = x AAx BB x 2 AB x BB q ma > 0. 1 (18) (20) x AA q ma + x AB q mb = x AA q A (19) (21) x BB q mb + x AB q ma = x BB q B 1 2 x AB x AA (x AA x BB x 2 AB )q mb = x AA (x BB q B x AB q A ) x AB q B x AA q A = x AAx BB x 2 AB x BB q ma 1 1 3 2 1 3 1 q A >q ma, q B >q mb 1 (18) (20) p A c A = x AA q ma x AB q mb = x AA q A x AA (q A q ma )= x AB q mb q A q ma = x AB x AA q mb (19) (21) p B c B = x BB q mb x AB q ma = x BB q B x BB (q B q mb )=x AB q ma q B q mb = x AB x BB q ma q A q ma = x AB x AA q mb > 0, q B q mb = x AB x BB q ma > 0
濱田弘潤 : 多角化企業の利潤分析 87 1 1 2 2 π A >π ma, π B >π mb 2 1 q A >q ma π A = x AA qa 2 >π ma = x AA q A q ma π B >π mb 2 (counter-intuitive) 2 1 1 (π A >π ma, π B >π mb ) 3
88 新潟大学経済論集第 85 号 2008- 英 3 π m >π A, π m >π B 3 π m = π ma + π mb = x AA q A q ma x BB q B q mb π A = x AA q 2 A π m π A = x AA q A (q ma q A ) x BB q B q mb 1 q ma q A = x AB x AA q mb (< 0) π m π A =(x AB q A x BB q B )q mb 1 x AB q A x BB q B = x AAx BB x 2 AB x AA q mb > 0 π m >π A π m >π B 3 2 3 3 1 2 3 2 3 2 2
濱田弘潤 : 多角化企業の利潤分析 89 2 6 2
90 新潟大学経済論集第 85 号 2008- 英 2008 I [1] (2007) M&A [2] (1997) M&A [3] (2005) NTT [4] Berger, P. and E. Ofek (1995) Diversification s Effect on Firm Value, Journal of Financial Economics, 37(1): 39 65. [5] Berger, P. and E. Ofek (1996) Bustup Takeovers of Value-Destroying Diversified Firms, Journal of Finance, 51(4): 1175 1200. [6] Besanko, D., D. Dranove, and M. Shanley (2003) Economics of Strategy,, 3rd edition, John Wiley & Sons: New York. (2002) 2 [7] Cabral, L. (2000) Introduction to Industrial Organization, MIT Press: Massachusetts. [8] Campa, J. and S. Kedia (2002) Explaining the Diversification Discount, Journal of Finance, 57(4): 1731 1762. [9] Chevalier, J. (2002) Why do Firms Undertake Diversifying Mergers? An Examination of the Investment Policies of Merging Firms, Working Paper, University of Chicago Graduate School of Business. [10] Comment, R. and G. Jarrell (1995) Corporate Focus and Stock Returns, Journal of Financial Economics, 37(1): 67 87. [11] Lang, L. and R. Stulz (1994) Tobin s q, Corporate Diversification, and Firm Performance, Journal of Political Economy, 102(6): 1248 1280. [12] Lins, K. and H. Servaes (1999) International Evidence on the Value of Corporate Diversification, Journal of Finance, 54(6): 2215 2239. [13] Matsusaka, J. (1993) Takeover Motives during the Conglomerate Merger Wave, RAND Journal of Economics, 24(3): 357 379. [14] Meyer, M., P. Milgrom, and J. Roberts (1992) Organizational Prospects, Influence Costs, and Ownership Changes, Journal of Economics and Management Strategy, 1(1): 9 35. [15] Milgrom, P. and J. Roberts (1990) The Efficiency of Equity in Organizational Decision Processes, American Economic Review: Papers and Proceedings, 80(2): 154 159. [16] Montgomery, C. and B. Wernerfelt (1988) Diversification, Ricardian Rents, and Tobin s q, RAND Journal of Economics, 19(4): 623 632. [17] Rajan, R., H. Servaes, and L. Zingales (2000) The Cost of Diversity: The Diversification Discount and Inefficient Investment, Journal of Finance, 55(1): 35 80. [18] Roberts, J. (2004) The Modern Firm: Organizational Design for Performance and Growth, Oxford University Press: Oxford. [19] Scharfstein, D. (1998) The Dark Side of Internal Capital Markets II: Evidence from Diversified Conglomerates, NBER Working Papers, 6352.
濱田弘潤 : 多角化企業の利潤分析 91 [20] Scharfstein, D. and J. Stein (2000) The Dark Side of Internal Capital Markets: Divisional Rent- Seeking and Inefficient Investment, Journal of Finance, 55(6), 2537 2564. [21] Singh, N. and X. Vives (1984) Price and Quantity Competition in a Differentiated Duopoly, RAND Journal of Economics, 15(4): 546 554. [22] Shin, H. H. and R. Stulz (1998) Are Internal Capital Markets Efficient?, Quarterly Journal of Economics, 113(2): 531 552. [23] Tirole, J. (1988) The Theory of Industrial Organization, MIT Press: Massachusetts. [24] Villalonga, B. (2002) Does Diversification Cause the Diversification Discount? Working Paper, Harvard University Graduate School of Business Administration. [25] Villalonga, B. (2004) Diversification Discount or Premium? New Evidence from the Business Information Tracking Series, Journal of Finance, 59(2): 479 506. [26] Vives, X. (1999) Oligopoly Pricing, MIT Press: Massachusetts.