Originally planning to pursue a major in economics, Zirui Song '06 found a way to marry his interestin that field with his passion for public health.
He first set out to examine the factors that prompt adolescents to start—and later stop—smoking, using an economic modeling technique known as “game theory.” Explains the public health major,
“I split the individual smoker into two decision-making entities, each with its own unique utility function and best-response in the game, or rather tug of war, of deciding whether or not to smoke at any time in a person’s life.”
He spent the summer after his sophomore year at the Brookings Institution in Washington, helping to develop an “agent-based model” under the tutelage of Hopkins Economics Professor Peyton Young. Song’s project looked specifically at teens within their social networks to examine whether one’s smoking behavior affects that of one’s friends and to what degree that influence exerts itself. The goal, says Song: to be able to “model the diffusion of behavior” over time. He’s hoping that the 20-page summary of his work will find its way to the working paper series at the Brookings Center on Social and Economic Dynamics.
“Brookings taught me that no matter how much research had been done on a subject, there is always a new way, a new angle, a new perspective with which to analyze it,” says Song, who founded Hopkins’ undergraduate public health journal, Epidemic Proportions, in 2003. “I see the world of knowledge as one big sphere. You never fully understand something until you have looked at it from every angle.”
In a second project on obesity, Song used “econometrics” to examine the post-surgical outcomes of patients at Union Memorial Hospital in Baltimore who had undergone gastric bypass surgery. Would participation in support groups in the months after surgery lead to better success in conquering their obesity? To find out, Song created several “linear multivariable models” and developed a questionnaire, which he distributed to patients to gather his data.
His findings, which he shared at a grand rounds presentation at Union Memorial: “Patients who spend time with each other in support groups lose more weight after surgery and keep it off longer.”