This paper investigates whether labor unions use proposals opportunistically to influence contract negotiations. Our empirical strategy relies on the observation that proposals have higher bargaining-chip value in contract expiration years, when a new contract must be negotiated. We find that in contract expiration years compared with nonexpiration years, unions increase their proposal rate by one-fifth, particularly proposals concerning executive compensation. Union proposals made during expiration years are less likely to be supported by other shareholders or a leading proxy advisor; the market reacts negatively to union proposals in expiration years; and withdrawn union proposals are accompanied by higher wage settlements. Received March 14, 2017; editorial decision July 19, 2018 by Editor Wei Jiang.