1. Faculty of Mannagement and Economics, Kunming University of Science and Technology, Kunming, 650093, China
2. Faculty of Ecomomics, Chiang Mai University, Chiang Mai, 50200, Thailand
3. Department of Applied Economics, University of Balearic Islands, Palma, 07122, Spain
4. Faculty of Management, Bournemouth University, Talbot Campus, Poole BH12 5BB, UK