We also use five other control variables in our models:
(1) To control for the possibility that a ‘‘newer’’ CEO is more likely to make changes
in employee contracts like the freeze decision, we include CEOTENURE, which
measures the number of years the CEO has served with the company.
(2) We use BMRATIO, or book-to-market ratio, to control for firm growth.
(3) We include leverage, LEV, measured as the ratio of total debt to total assets, as
bond contracts and covenants could potentially motivate the freeze decision.
(4) Although we match firms by size, we also include the variable, SIZE, measured
as log of total assets, as the matching process in some models is hampered by
missing data.
(5) We control for UNION, a dummy variable equal to 1 if a firm sponsors any
collectively bargained DB plans, as firms with strong unions are less likely to
have the leeway to freeze their DB plans[18].