This thesis contains three empirical essays. It is mainly motivated by the economic situations (low economic growth and high economic inequality) of many developing countries including Thailand. Nonetheless, the labour supply literature regarding developing countries necessary to address these issues is very limited. The first empirical chapter investigates the determinants of labour supply at the extensive margin in the formal labour market of Thailand as a developing country. This chapter applies the structural binary probit to model behaviour of labour supply participation using the Household Socio-Economic Survey (HSES) of Thailand covering 2009, 2011, 2013, and 2015. The key focuses are the role of the informal sector, the effect o...