We examine security price reactions around the announcements of 123 voluntary spin-offs by 116 firms between 1963 and 1981 involving a pro-rata distribution of the common stock of a subsidiary to the stockholders of the parent firm. The median spin-off in the sample is 6.6% of the original equity value and is associated with an abnormal return of 7.0% from 50 days prior to the announcement through completion of the spin-off. No evidence is found to indicate the gains to stockholders represent wealth transfers from senior securityholders. Over the entire event period we find positive gains for firms engaging in spin-offs to facilitate mergers or to separate diverse operating units but negative returns to firms responding to legal and/or regulatory difficulties. In the two-day interval surrounding the first press announcement we find positive average excess returns for all groups.

We investigate the valuation consequences of voluntary proposals to sell part or all of a corporation's assets. For partial sell-offs, successful sellers and buyers reap statistically significant abnormal returns of 1.66% and 0.83%, respectively. Unsuccessful sellers realize gains at the bid announcement of 1.41% that are lost at the offer termination. In contrast, proposals to liquidate the firm are associated with significant average abnormal returns of 12.24%. We interpret these findings as evidence that asset sales are associated with the movement of resources to higher-valued uses rather than as evidence of market mispricing before the divestiture announcements.