Færre børsnoterede selskaber ændrer på industristruktur

Et forskningspapir påviser, at et markant fald i andelen af børsnoterede selskaber i USA de seneste årtier har haft stor effekt på industristrukturen. Det har blandt andet betydet, at koncentrationen i visse brancher er stærk øget, og det har givet forøgede profitmarginer og unormalt højere aktieafkast (og sikkert mindre konkurrence og højere salgspriser). De brancher, som har ”mistet” flest børsnoterede selskaber, har samtidig haft lettere ved at foretage investeringer gennem opkøb af andre virksomheder: ”There has been a systematic decline in the number of publiclytraded firms over the last two decades. Half of the U.S. industries lost over 50% of their publicly traded peers. The decline has increased industry concentration, as the void left by public firms has not been filled by an increase in the number of private businesses or by greater presence of foreign firms. Firms in industries with the largest decline in the number of firms have generated higher profit margins and abnormal stock returns, and enjoyed better investment opportunities through M&A deals. Overall, our findings suggest that the nature of US product markets has undergone a structural shift that has potentially weakened competition.”