Hummy Song is a PhD candidate in Health Policy Management at the Harvard Graduate School of Arts and Sciences and Harvard Business School. Her research focuses on health care operations, coordination, and the productivity of the health care workforce. She is currently working on projects that examine various operational and organizational factors that may affect worker productivity and quality of care. Her research utilizes large datasets derived from electronic medical record systems, hospital inpatient databases, and surveys of the health care workforce.
Hummy has worked with several hospitals and health care organizations both in the U.S. and in developing countries. Prior to her graduate studies, she worked with global health organizations on randomized control trials and observational studies.
Hummy received an AB in History with a secondary field in Psychology from Harvard College. She holds an MPP from the Harvard Kennedy School of Government, where she focused on global health and development policy. Prior to her master’s program, she worked with the Campaign for Tobacco-Free Kids on international tobacco control policy development and implementation. She also worked as a policy analyst at The Century Foundation.
Cohort Turnover and Productivity: The July Phenomenon in Teaching Hospitals
We consider the impact of cohort turnover—the planned simultaneous exit of a large number of experienced employees and a similarly sized entry of new workers—on productivity in the context of teaching hospitals. Specifically, we examine the impact of the annual July turnover of residents in American teaching hospitals on levels of resource utilization and quality in teaching hospitals relative to a control group of non-teaching hospitals. We find that, despite the anticipated nature of the cohort turnover and the supervisory structures that exist in teaching hospitals, this annual cohort turnover results in increased resource utilization (i.e., longer length of hospital stay) for both minor and major teaching hospitals, and decreased quality (i.e., higher mortality rates) for major teaching hospitals. Particularly in major teaching hospitals, we find evidence of a gradual trend of decreasing performance that begins several months before the actual cohort turnover and may result from a transition of responsibilities at major teaching hospitals in anticipation of the cohort turnover.
Groups and Teams;
Health Care and Treatment;
Resignation and Termination;
The Diseconomies of Queue Pooling: An Empirical Investigation of Emergency Department Length of Stay
We conduct an empirical investigation of the impact of two different queue management systems on throughput times. Using an Emergency Department's (ED) patient-level data (N = 231,081) from 2007 to 2010, we find that patients' lengths of stay (LOS) were longer when physicians were assigned patients under a pooled queuing system, compared to when each physician operated under a dedicated queuing system. The dedicated queuing system resulted in a 10 percent decrease in LOS—a 32-minute reduction in LOS for an average patient of medium severity in this ED. We propose that the dedicated queuing system yielded shorter throughput times because it provided physicians with greater ability and incentive to manage their patients' flow through the ED from arrival to discharge. Consistent with social loafing theory, our analysis shows that patients were treated and discharged at a faster rate in the dedicated queuing system than in the pooled queuing system. We conduct additional analyses to rule out alternate explanations, such as stinting on care and decreased quality of care. Our paper has implications for health care organizations and others seeking to reduce throughput time, resource utilization, and costs.
Management Practices and Processes;
Health Care and Treatment;
Awards & Honors
Thomas T. Hoopes Prize:
Won the 2008 Thomas T. Hoopes Prize which is awarded to Harvard undergraduates on the basis of outstanding scholarly work or research.