This book filters the advancements in economic growth theories with the purpose of translating them into more accessible language. In order to be useful to undergraduate students mathematics was reduced to the minimum needed to assure the working of the deductive method and to facilitate the articulation between different models. With the same purpose of being useful to the undergraduate students, we include an introductory chapter about basic concepts and measurement problems, which is usually absent in Economic Growth textbooks. But, the fact that the book is directed at undergraduate students doesn’t mean that it cannot be helpful for other potential users. Given the rigorous methodology used, graduate students may find it useful as an introduction and a complement to the more sophisticated presentations available in articles and advanced books. Essentials of Economic Growth is divided into seven chapters. Every chapter follows the same outline. It begins with a box that contains several questions to motivate study. Next, specific subjects are analysed and discussed. Chapter ends with a summary and conclusions section, followed by exercises and review questions, which allow students to test their learning. Chap. 1. Well-being and the wealth of nations. Well-being and wealth; wealth of economies and wealth measurement; International comparability methodologies: the market exchange rate, the Atlas method and the purchasing power parity; Nominal and real measures, exchange rate deviation index and comparative price level; Limitations of GDP per capita and the human development index; Different ways of computing growth rates; Distribution of income across countries and regions. Chap. 2. The first growth models: From Smith to Harrod-Domar What is a model? Concepts; Economic growth in the classics: Adam Smith and the progressive state; Ricardo’s model as the first modeled theory of growth; assumptions and the model dynamics; The Harrod-Domar growth model: short run and long run dynamic equilibrium. Chap. 3. Replies to the Harrod-Domar model: the search for dynamic equilibrium The neoclassical reply: the Solow growth theory; assumptions; dynamic equilibrium; properties of “steady-state”; Post-Keynesian extensions: the Kaldor model; the Pasinetti amendment. Chap. 4. Explaining growth per capita: the Solow model and the stylised facts of economic growth Growth models and TP (technical progress): neutral TP; definitions of neutrality; The Solow model with technical progress; steady state equilibrium; properties of steady state; transitional dynamics; The Solow model and the empirics of growth; the sources of growth approach; the growth accounting; Kaldor’s stylized facts and the Solow model. Chap. 5. Growth empirics: Convergence and the extensions of the neoclassical growth model The convergence debate; absolute convergence and conditional convergence; -convergence and -convergence; Extensions and empirical applications of the neoclassical growth model; Human capital and growth; the MRW model; the Solow model with human capital; The Robert Barro’s contribute to growth empirics; rationale; main empirical results. Chap. 6. Endogenous Growth: The power of externalities The AK Model; Knowledge as an engine of growth; increasing returns to scale and externalities; Externalities as a compensation for diminishing returns; The first model of Romer: learning by doing externalities; model specification and results; decentralized equilibrium and the social optimum; The Lucas model: human capital production and externalities; model specification and results; decentralized equilibrium and the social optimum. Chapter 7. Endogenous Technical Progress Knowledge and innovation; imperfect competition and differentiation; The ideas driven growth model: model specification; solution; consistency of the main results; Reconsideration of the ideas production function; Is economic growth driven by ideas? Conclusion: What is the engine of growth