TY - JOUR A1 - Deng, Y. A1 - Hillygus, D.S. A1 - Reiter, J.P. A1 - Si, Y. A1 - Zheng, S. T1 - Handling attrition in longitudinal studies: The case for refreshment samples Y1 - 2013 DO - 10.1214/13-STS414 VL - 28 IS - 2 ER -