1. a Lecturer, Community Health Development Program, Graduate School, Nakhon Ratchasima Rajabhat University and PhD Candidate, Faculty of Public Health , Khon Kaen University , Thailand
2. b Associate Professor, Faculty of Public Health , Khon Kaen University , Thailand
3. c Research Fellow, Population Studies Centre, University of Waikato and PhD Candidate, Department of Economics , University of Waikato , NZ
4. d Senior Lecturer, Department of Economics , University of Waikato , NZ