1. Department of Sociology, Texas State University, San Marcos, TX 78666, USA
2. Department of Social Welfare, Institute of Social Welfare, Kongju National University, Gongju-si 32588, Republic of Korea
3. Edward R. Roybal Institute on Aging, Suzanne Dworak-Peck School of Social Work, University of Southern California, Los Angeles, CA 90007, USA
4. Department of Social Welfare, Ewha Womans University, Seoul 07985, Republic of Korea