on aging.⁴ The cross-section data from the household surveys have contributed significantly in understanding the current status and situation of the older population in Thailand, both by researchers and policymakers. However, to understand the aging process of the population is a life-course study that involves specialists in multi-and interdisciplinary fields, such as demography, epidemiology, health, psychology, economics, sociology, and survey methodology. An intensive database from each round of the survey and from the same sample households and individuals in each dimension will enhance knowledge about the process of aging biologically, psychologically, sociologically, and economically.

A national longitudinal study using panel data to formulate scientific knowledge on aging and to inform public policy, such as the Health and Retirement Study (HRS) conducted by the University of Michigan, has not been carried out nor has it been an interest of Thai researchers. Such a survey would be complicated, time-consuming, and costly to collect, maintain, and disclose the data, which may be the main reason preventing NSO or other research organizations in Thailand from conducting a large-scale longitudinal panel survey on the older population. Yet, longitudinal studies using panel data like the HRS have contributed significantly to advances in knowledge about demography, economics, sociology, and epidemiology of aging. Currently, HRS has become the pathbreaker for longitudinal and panel studies on aging around the globe⁵ (Hauser and Willis, 2004, 2011).

During 2006-2007, a group of researchers at the National Institute of Development Administration saw the value of a large-scale longitudinal study of aging like the HRS and attempted to establish a similar study in Thailand. A proposal for a pilot project, titled the Panel Survey and Study on Health, Aging, and Retirement in Thailand (HART), was developed in 2008 and received a one-year research grant from the National

⁴The national cross-section survey on aging was conducted bi-annually with a sample size of 79,500 households by interviewing each member aged 50 and older. The questionnaire is composed of various dimensions: demography, living conditions, employment and income, health and healthcare, social activities, information access, transfer and visit, knowledge in elderly care, and household asset ownership.

⁵HRS’ contribution to the scientific knowledge of aging has influenced the development of large-scale longitudinal studies in many countries. These include the Mexican Health and Ageing Study (MHAS), English Longitudinal Study of Ageing (ELSA), Korean Longitudinal Study of Ageing (KLoSA), Japanese Study of Aging and Retirement (JSTAR), China Aging and Retirement Longitudinal Study (CHARLS), and Longitudinal Aging Study for India (LASI) (Hauser and Weir, 2011).