How and to what extent does regulation matter in shaping corporate behavior? How important is it compared to other incentives and mechanisms of social control, and how does it interact with those mechanisms? How might we explain variation in corporate responses to law and other external pressures? This article addresses these questions through an study of environmental performance in 14 pulp and paper manufacturing mills in Australia, New Zealand, British Columbia, and the states of Washington and Georgia in the United States. Over the last three decades, we find tightening regulatory requirements and intensifying political pressures have brought about large improvements and considerable convergence in environmental performance by pulp manufacturers, most of which have gone "beyond compliance" in several ways. But regulation does not account for remaining differences in environmental performance across facilities. Rather, "social license" pressures (particularly from local communities and environmental activists) and corporate environmental management style prod some firms toward better performance compliance than others. At the same time, economic pressures impose limits on "beyond performance" investments. In producing large gains in environmental performance, however, regulation still matters greatly, but less as a system of hierarchically imposed, uniformly enforced rules than as a coordinative mechanism, routinely interacting with market pressures, local and national environmental activists, and the culture of corporate management in generating environmental improvement while narrowing the spread between corporate leaders and laggards.