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.

Previous estimates of a ‘size effect’ based on daily returns data are biased. The use of quoted closing prices in computing returns on individual stocks imparts an upward bias. Returns computed for buy-and-hold portfolios largely avoid the bias induced by closing prices. Based on such buy-and-hold returns, the full-year size effect is half as large as previously reported, and all of the full-year effect is, on average, due to the month of January.

Recent empirical work by Banz (1981) and Reinganum (1981) documents abnormally large risk-adjusted returns for small firms listed on the NYSE and the AMEX. The strength and persistence with which the returns appear lead both authors to conclude the single-period, two-parameter capital asset pricing model is misspecified. This study (1) confirms that total market value of common stock equity varies inversely with risk-adjusted returns, (2) demonstrates that price per share does also, and (3) finds that transaction costs at least partially account for the abnormality.

This paper investigates the rationale behind interfirm tender offers by examining the returns realized by the stockholders of firms that were the targets of unsuccessful tender offers and firms that have made unsuccessful offers. Our results suggest that the permanent positive revaluation of the unsuccessful target shares [documented by Dodd and Ruback (1977) and Bradley (1980)] is due primarily to the emergence of and/or the anticipation of another bid that would ultimately result in the transfer of control of the target resources. We also find that the rejection of a tender offer has differential effects on the share prices of the unsuccessful bidding firms depending upon whether the tender offer process results in a change in the control of target resources. On the basis of these results we conclude that acquisitions via tender offers are attempts by bidding firms to exploit potential synergies, not simply superior information regarding the ‘true’ value of the target resources.