Essays on endogenous growth : technology and financial markets

In Chapter 1 I modify a standard quality ladder model by assuming that R&D is driven by outsider firms and the winners of the race sell licenses over their patents to the intermediate firms. These ones compete à la Cournot and strategic complementarities on costs are assumed. I prove that there exists an interval of values of the spillover parameter such that the relationship between competition and growth is an inverted-U-shape. I finally run a calibration of the model for the UK economy and find that the calibrated value of the spillover parameter lies in the region where the the relationship between competition and growth is non-monotonic. In Chapter 2 I consider a model of horizontal differentiation with a general production function where the parameter of competition is disentangled from that representing the degree of specialization and I study aggregate welfare as a function of the degree of competition by solving in closed form a model of horizontal differentiation. I find that welfare is a bell-shaped function of competition thanks to the interaction of a positive short run effect on current consumption and a negative long run effect on growth. In the last chapter I develop a small open economy model of endogenous growth in which government can finance productive public expenditures by levying income tax and by borrowing on imperfect international finacial markets where foreign debt is constrained by fiscal revenue and international lenders can just seize a fraction of collaterals in case of debt repudiation. In order to switch to the binding regime, where a BGP exists, I show that, consistently with the empirical literature, the economy can fully enjoy the advantages of financial openess only if it has attaind a certain treshold of institutional and financial development and economic features. I run numerical simulations in order to find the endogenous switching date. Finally, the optimal public spending-GDP ratio is greater than that of literature and if financial markets imperfections are not too weak, countries with a high TFP experience higher growth rates under the flow-based collateral assumption than under stock-based collaterals. Otherwise the international interest rate must be sufficiently high.(ECON 3) -- UCL, 201