This work comprises four essays in two related areas: labor and development economics. On the labor side, two essays study (i) the effects of sizeable policy reforms over labor informality and (ii) the relation between productivity and wages in a context of substantial informality and high turnover rates. On the development side, two essays provide a comparison between developed and developing countries in the following aspects: (iii) the degree of complementarity of production factors and their capacity to translate R&D investments into economic growth and (iv) the effects of fiscal redistribution over income inequality. Within the context of Latin America - the most income-unequal and labor-informal region in the world - this work intends to augment the understanding of the behavior, dynamics, interactions and contributions of productive factors (labor and innovative capital) and the effects that policies aimed at formalizing labor, innovating capital or redistributing factors retributions may have. The study applies recent measurement techniques and exploits rich novel datasets which combined with reformulated models help us to propose alternative appealing explanations. Lessons learnt from these four essays suggest that (i) job dynamics play a fundamental role in the success (or failure) of policies aimed at promoting labor formality. Against the conventional wisdom, we contend that reductions in hiring rather than increases in separation rates are the main determinants of informality increases following protectionist policies. (ii) Job dynamics also play a differentiating role in the determination of wage-productivity elasticities and income risk (with new hires reacting more than incumbents). (iii) Yet, returns of labor and physical capital are constant across countries and periods regardless the stage of development whereas they exhibit an inverted U shape for technological capital (this is, highest returns observed for mid developed cases). (iv) Comparable private returns of productive factors are mirrored in comparable market income inequality measures observed across some developed and developing regions. However, while in Europe fiscal redistribution helps to achieve better distributed disposable income, in Latin America fiscal redistribution has meager or even countervailing effects.