The opioid epidemic is a source of deep national anguish in the United States: It now kills almost 100 Americans each day, more than motor vehicle accidents. President Donald Trump today officially declared the epidemic a national public health emergency. Although he hasn’t allocated any additional federal funding to address the crisis, the announcement could accelerate efforts at the federal, state, and local levels to identify and implement ways to combat it. As his administration strives to galvanize efforts, it would benefit from drawing on the growing body of research that examines the medical and economic origins and effects of the crisis.