No description available.

No description available.

Les systèmes complexes sont présents partout dans notre environnement : internet, réseaux de distribution d'électricité, réseaux de transport. Ces systèmes ont pour caractéristiques d'avoir un grand nombre d'entités autonomes, des structures dynamiques, des échelles de temps et d'espace différentes, ainsi que l'émergence de phénomènes. Ce travail de thèse se focalise sur la problématique du contrôle de tels systèmes. Il s'agit de déterminer, à partir d'une perception partielle de l'état du système, quelle(s) actions(s) effectuer pour éviter ou au contraire favoriser certains états globaux du système. Cette problématique pose plusieurs questions difficiles : pouvoir évaluer l'impact au niveau collectif d'actions appliqués au niveau individuel, modéliser la dynamique d'un système hétérogène (plusieurs comportements différents en interaction), évaluer la qualité des estimations issues de la modélisation de la dynamique du système. Nous proposons une architecture de contrôle selon une approche " equation-free ". Nous utilisons un modèle multi-agents pour évaluer l'impact global d'actions de contrôle locales avant d'appliquer la plus pertinente. Associée à cette architecture, une plateforme a été développée pour confronter ces idées à l'expérimentation dans le cadre d'un phénomène simulé de " free-riding " dans les réseaux d'échanges de fichiers pair à pair. Nous avons montré que cette approche permettait d'amener le système dans un état où une majorité de pairs partagent alors que les conditions initiales (sans intervention) feraient évoluer le système vers un état où aucun pair ne partage. Nous avons également expérimenté avec différentes configurations de l'architecture pour identifier les différents moyens d'améliorer ses performances.

This dissertation is devoted to the analysis of various aspects of inefficiency in the political economy. It consists of four self-containing theoretical essays. The first two chapters deal with the interplay between inefficiency and commitment. Chapter 1 studies the problem of commitment in autocratic regimes and its implications for growth. Chapter 2 argues that the absence of commitment undermines the validity of the Coase theorem. The next two chapters address alternative sources of inefficiency, abstracting from commitment-related problems. Chapter 3 discusses inefficiencies arising in organizations whose members possess veto power and suggests a way of mitigating the problem. Finally, Chapter 4 analyzes the impact of demand linkages on the efficiency of lobbying for trade policy. Chapter 1. “Autocracy, Devolution and Growth” Some autocracies have sustained high economic growth for many decades; others have stagnated at low levels of production. Paradoxically, the stagnating autocracies appear to possess more natural resources and be more resistant to political change than the growing autocracies. The paper argues that the scope for capital accumulation and growth in an autocracy is largely determined by the autocrat's incentive to cling to power. The main result of the paper is that there will be private capital accumulation only if the autocrat’s benefits from political control are not too high. The reason is that, as capital accumulates and growth slows down, the autocrat faces an increasing temptation to expropriate the capitalists. Since expropriation eliminates growth, the autocrat may voluntarily refrain from expropriating if future growth is sufficiently large; otherwise, the temptation to expropriate can only be resisted through a credible commitment, that is, by devolving some political power. For autocrats with large benefits of control, for example valuable natural resource rents, devolution of power may always be unattractive. As a result, capitalists realize that they will eventually be expropriated, and capital accumulation therefore never starts. On the other hand, autocrats with small resource rents will eventually devolve power, since this commitment is necessary to sustain growth. Therefore, capitalists are willing to start accumulating despite the autocratic regime. In other words, autocracies are vulnerable to the resource curse.   Chapter 2. “The Coase Theorem Is False” (with Tore Ellingsen) The paper provides simple and robust counterexamples to the Coase Theorem. More precisely, we show that equilibrium investments in club goods can be suboptimally small despite the presence of well-defined and perfectly protected property rights and the absence of transaction costs and informational asymmetries. The reason is that, in equilibrium, a club of owners will typically not exercise their right to exclude outsiders, preferring instead to exercise their right to sell access. As long as the club of owners does not have all the bargaining power in such ex post access negotiations, strategic non-membership provides a valuable free-riding opportunity. Chapter 3. “Club-in-the-Club: Reform under Unanimity” (with Erik Berglöf, Mike Burkart and Guido Friebel) In many organizations, decisions are taken by unanimity. We analyze a model of an organization in which members with heterogeneous productivity privately contribute to a common good. Under unanimity, the least efficient member imposes her preferred effort choice on the entire organization. In the presence of externalities and an incomplete charter, the threat of forming an “inner organization” can undermine the veto power of the less efficient members and coerce them to exert more effort. We identify the conditions under which the threat of forming an inner organization is never executed, and under which inner organizations are equilibrium outcomes, and provide a rationale for the diversity of decision rules. Chapter 4. “Protection for Sale to Oligopolists” This paper modifies Grossman and Helpman’s "Protection for Sale" model by allowing demand linkages and oligopolistic competition. It shows that increased substitutability between products weakens interest groups’ incentives to lobby. For the case of two industries it obtains a particularly simple result: the protection of the organized industry’s product falls, whereas the protection of the unorganized industry’s product increases with product substitutability. The model suggests that empirical studies of the "Protection for Sale" may overstate the lobby groups’ desire for protection. / Diss. Stockholm : Handelshögskolan, 2006

No description available.

No description available.

Since the Civil War, historians have tried to understand why eleven southern states seceded from the Union to form a new nation, the Confederate States of America. What compelled the South to favor disunion over union? While enduring stereotypes perpetuated by the Myth of the Lost Cause cast most southerners of the antebellum era as ardent secessionists, not all southerners favored disunion. In addition, not all states were enthusiastic about the prospects of leaving one Union only to join another. Secession and disunion have helped shape the identity of the imagined South, but many Georgians opposed secession. This dissertation examines the life of U.S. Supreme Court Justice James Moore Wayne (1790-1867), a staunch Unionist from Savannah, Georgia. Wayne remained on the U.S. Supreme Court during the American Civil War, and this study explores why he remained loyal to the Union when his home state joined the Confederacy. Examining the nature of Wayne’s Unionism opens many avenues of inquiry into the nature of Georgia’s attitudes toward union and disunion in the antebellum era. By exploring the political, economic and social dimensions of Georgia Unionism and long opposition to secession, this work will add to the growing list of studies of southern Unionists.

The thesis consists of four papers. The first two essays deal with entry externalities, the third studies the Law of One Price (LOP), while the last essay examines average profits for a monopolist under uncertainty. In the first essay, entry externalities in the form of information and positive payoff externalities are studied. When a firm enters a market, it often imposes externalities on existing firms and/or future potential entrants. If products are substitutes, these externalities are typically negative; if products are complements, the externalities are typically positive. Externalities related to substitution or complementarities between products are called payoff externalities, since entry by one firm has a direct effect on the other firms' payoff. Another type of externality arises when firms have private information about the profitability of entry. In this case, the entry decision of one firm potentially reveals that firm's private information. The focus of the paper is on the scope for intervention for an uninformed social planner, when firms privately know the profitability of entry and moreover, the firms have an option to delay their entry. The main result is that there is insufficient entry, since firms delay too much in equilibrium and further, the social planner can increase welfare by subsidizing early entry. Continuing on this theme, the second essay has the same focus, but instead takes the time of entry as fixed, while generalizing the analysis of payoff externalities also to the case of negative payoff externalities. The main contribution is the characterization of equilibria under both positive and negative payoff externalities and the implications for public policy. Here, the scope for intervention will, in contrast to the results in the first essay, be low, when entry is profitable for uninformed firms. In the third essay (joint with Richard Friberg), deviations from the LOP are studied in the presence of transport costs, under the assumption that firms can endogenously choose to segment markets in order to prevent arbitrage by consumers. It is shown that the deviation from LOP can increase as transport costs fall between countries. The last essay (joint with Richard Friberg), studies the problem facing a monopolist when the cost of inputs is uncertain. The main result is that the monopolist can gain from this uncertainty, in the sense that average profits are increasing in the variability of costs. / Diss. Stockholm : Handelshögsk., 2001

No description available.

No description available.