The authors measured perceptions of safety climate, motivation, and behavior at 2 time points and linked
them to prior and subsequent levels of accidents over a 5-year period. A series of analyses examined the
effects of top-down and bottom-up processes operating simultaneously over time. In terms of top-down
effects, average levels of safety climate within groups at 1 point in time predicted subsequent changes
in individual safety motivation. Individual safety motivation, in turn, was associated with subsequent
changes in self-reported safety behavior. In terms of bottom-up effects, improvements in the average
level of safety behavior within groups were associated with a subsequent reduction in accidents at the
group level. The results contribute to an understanding of the factors influencing workplace safety and
the levels and lags at which these effects operate.