Essay on natural resources, economic growth, development and equity.

Summary Sustainable development is an attractive topic for economists. In the literature on economic growth and sustainable development, two basic approaches are used in most discussions. The first is to recognize the importance of natural resources as well as the strategies for using these resources for economic development in the context of their depletion. The second is the issue of intergenerational equity in which the needs of present generations can be met without compromising the ability to meet the needs of future generations. My thesis aims to investigate theoretical models of natural resources, economic growth, development, and equity. Chapter 1 examines a two-sector economy with externalities. We study a theoretical model that investigates the relationship between the optimal dynamics of economic growth using renewable resources and environmental quality. In this model, the industrial sector uses intermediate inputs to produce a final consumption good, and another sector, called the exploitation sector, engages in the exploitation of a renewable resource. This resource can be sold directly at an exogenously determined market price, generating an additional source of revenue. We also take into account the negative externalities of the polluting industrial sector on the regeneration capacity of the renewable resource sector. Without the usual convexity or super-modularity, we prove that the economy evolves to increase the net stock gain sometime in the future. This property ensures that in the long run. The economy is very close to a steady state. We also establish the conditions that ensure that the economy converges in the long run. For sustainable development, one of the most difficult problems related to the criteria of the social welfare function is the reconciliation between equality and efficiency. The Axiom of Anonymity states that social order is invariant to information about individual orders. The Pareto axiom dictates that if at least one generation increases its utility, social welfare must improve. However, no SWF satisfies both the anonymity and Pareto axioms. To overcome this difficulty, some authors propose several approaches to mitigate these axioms. Consequently, many criteria have been introduced, such as: dominance, weak dominance, weak pareto, monotonicity, etc. In the second chapter of my thesis, we revisited some properties of a SWF in the literature, taking into account the continuity of this SWF under different topologies. Moreover, we propose the notions of weak and strong non-dictatorship of the present and future in the spirit of Chichilniski, and provide a detailed description of the parameters characterizing the two non-dictatorships. In chapter 3, we study an inter-temporal optimization problem using a criterion that is a combination of the Ramsey and Rawls criteria. A detailed description of the behavior of the economy over time is provided.[...] The last chapter develops a theoretical model to access the determinants of the efficiency of the Special Economic Zone and the conditions for its implementation. The results of this study show that there is a threshold such that for all initial economies of a country above this level, it will be optimal to invest in new technologies. Moreover, several factors including the price of technology capital, the wage of highly skilled labor, the initial income of the economy, and total factor productivity in the SEZ sector endogenously determine this threshold.