Does Section 16b deter insider trading by target managers?

Abstract

This paper examines empirically whether the short-swing rule (Section 16b of the Securities Exchange Act) deters managers from trading before mergers. Since a merger forces the sale of the target's outstanding equity, insider purchases within six months before the merger cannot escape this rule. We examine the 1941–1961 period when no other insider trading laws were enforced. Consistent with 16b's deterrent effect, managers' purchases drop significantly before the announcement. Before completion, the decrease occurs only in the 1941–1955 period. Surprisingly, pre-announcement sales do not decline, even though 16b cannot punish deferral of planned sales.