From the abstract:
Nursing: Supply and Demand through 2020 analyzes the growing need for qualified nurses. The study projects that the economy will create 1.6 million job openings for nurses through 2020. Yet, there will not be enough nurses to fill those openings. We project the nursing workforce will be facing a shortfall of roughly 200,000 nursing professionals by 2020.
One of the reasons for the growing demand is due to changing demographics; older nurses are retiring in large numbers, creating thousands of job openings. Another factor is the Affordable Care Act, which expands health insurance coverage to millions of job openings. In addition, nursing schools lack the faculty, facilities, and training sites to match the growing demand.