This thesis, consisting of four essays, studies various aspects of structural transformation based on a dual economy approach. The first is on the relationship between economic growth and structural change. I introduce a dual growth model with heterogeneous labour, and show that uneven sectoral growth shifts workers' comparative advantage, inducing selective migration from agriculture to non-agriculture. This transition determines sectoral labour compositions over time, and influences the dynamics of growth paths. Simulations suggest an inverse correlation between the speed of structural change and the relative dispersion of productivity across workers. The second essay provides further insights for the dynamics of living standards during structural transformation. The time paths of welfare, inequality and poverty are simulated under a hypothetical structural change. The model shows a Pareto-improvement of welfare, rise on inequality, and reductions on poverty over time for both agriculture and non-agriculture, but the effects are uneven. It is argued that economic transformation is not necessarily associated with a Kuznets curve. The third essay studies the interactions between labour markets and rural-urban selective migration. I recast the dual economy model with a search and matching framework for its urban sector, and show a link between the size of the urban informal sector and individual productivity distributions. It suggests that improving average individual skills is an effective way to alleviate urban underemployment. The last essay examines the conditions under which foreign transfers to households could promote economic growth and structural change. Although transfers can bring welfare benefits, the effects on growth and structural change are modest under isoelastic utility, but larger effects emerge when preferences take the Stone-Geary form.