This thesis is an investigation into the microeconomic mechanisms that govern some of the occupational choices faced by workers in Sub-Saharan Africa, and into the monetary and non-monetary returns to their decisions. Chapter 1 begins by exploring the decision process that leads workers to allocate themselves to different occupations within the economy. In particular, I investigate the role of risk-aversion in the allocation of workers between formal and informal jobs in Ghana, hence attempting to explain a fundamental dimension of duality through an investigation into workers' preferences. In my model of sectoral allocation risk-averse workers can opt between entering the free-entry informal sector and queuing for formal occupations. Conditional on identifying the riskier option, the model yields testable implications on the relationship between risk-aversion and workers' allocation. My testing strategy proceeds in two steps. First, using the first three waves of the Ghana Household Urban Panel Survey (GHUPS) dataset, I estimate expected income uncertainty and find it considerably higher in the informal sector than in formal employment. Second, using experimental data to elicit risk-attitudes I estimate the effect of risk-aversion on occupational choices and I find that, in line with the first result, more risk-averse workers are more likely to queue for formal jobs and less likely to be in the informal sector. The conclusion of the first chapter is that attitudes to risk should feature more prominently in models of sector allocation and in the design of labour market policies, in particular when those policies aim to impact workers' vulnerability to risk and uncertainty. Chapter 2 focuses on the largest occupational category in the Developing world, self-employed workers with small productive activities, and it tries to estimate the returns to different productive assets, namely physical capital, labour and human capital. These are the workers that form most of the informal sector analysed in chapter 1, which allows me to draw a direct link with the analysis so far. The chapter begins by specifying a model for the income-generating process grounded in the literature on firms' production and hence abridging the gap between the analysis of individual earnings and the study of firms' value added. Identification in the empirics is achieved by means of panel estimators that are suitable to address the endogeneity of input choices, which derives from both time-varying and time-invariant unobservable heterogeneity. The use of these estimators is made feasible by the length of the Ghanaian Household Urban Panel Survey dataset at CSAE. I also explore issues of endogeneity in the selection of different technologies, defined by their relative capital and labour intensity. Finally, I analyse the shape of returns to capital, with the aim to detect potential non-convexities in technology. The results show that capital and work-experience play the strongest role in income-generation, while the shares of value added attributed to labour and to formal schooling are low. Marginal returns to investment are high at low capital levels and they decrease very rapidly, pointing against the existence of non-convexities due to minimum scale requirements, but implying that real income gains resulting form micro-investment are modest. Chapter 3 returns to the issue of earnings uncertainty and risk-aversion explored in Chapter 1, but it now takes the allocation choice as given and explores the direct welfare implications of income uncertainty for worker's well-being. Namely, the chapter explores the relationship between income and welfare, with a particular attention on the link between income vulnerability and happiness. Using unique longitudinal data on life-satisfaction and labour market outcomes, I estimate an individual measure of vulnerability (defined as the probability of falling below a low-income threshold) and investigate its effect on well-being. After controlling for unobservable individual fixed effects, work-satisfaction, relative income and other relevant worker characteristics, I find a sizable impact of vulnerability, over and above the income effect. When I explore the mechanisms behind my results, I find that aspiration adaptation to current income may result in a transitory income effect. Moreover, using my direct measure of attitudes to risk from field-experiments (already used in chapter 1), I can test directly the hypothesis that more risk-averse agents suffer more heavily from a given increase in income vulnerability. Overall, my findings support policy interventions that aim to reduce vulnerability, as I expect such policies to have a 'direct' impact on agents' happiness given the prevailing attitudes to risk and uncertainty in the population. Finally, from the point of view of overall social welfare, my results suggest that non-Rawlsian growth models, whereby 'someone may be left behind', may fail to enhance general welfare, for high enough levels of risk-aversion in the population, if the risk of falling behind is sufficiently widespread.