BOURGEON Jean Marc

Crop biodiversity has the potential to enhance resistance to strains due to biotic and abiotic factors and to improve crop production and farm revenues. To investigate the effect of crop biodiversity on crop productivity, we build a probabilistic model based on ecological mechanisms to describe crop survival and productivity according to diversity. From this analytic model, we derive reduced forms that are empirically estimated using detailed field data of South African agriculture combined with satellite derived data. Our results confirm that diversity has a positive and significant impact on crop survival odds. We show the consistency of these results with the underlying ecologic and agricultural mechanisms.

Under moral hazard, most insurance contracts are incomplete, to the extent that they condition the coverage neither on the contingencies under which policyholders choose their behavior, nor on the circumstances of the loss. This incompleteness can be explained by underwriting and auditing costs borne by insurers, by policyholders cognitive costs, and by the limits of market regulation. It opens the door to controversies and disputes between insured and insurer. In this context, we analyze how insurance law can mitigate moral hazard, by allowing insurers to cut indemnities in some circumstances, while preventing them from excessive nitpicking. We also highlight conditions under which the burden of proof should be on the policyholders, provided that insurers are threatened by bad faith penalties.

We consider a country whose government provides a bundle of goods and services through a multi-tier administrative organization. We compare the optimal architectures of public governance (i.e. the division of the state into several tiers, the distribution of services among them, their number of jurisdictions and the performance ability of their administrations) of two governments, one centralized and the other decentralized. Under a decentralized government, national and subnational decision-makers only consider the impact of their decisions on the welfare of their constituents, neglecting other tiers' policy. The resulting architecture is generally different from the (first-best) centralized one, and depends on how citizens weight the performance ability of the administrations and the range of goods they provide. If the relative weight on the performance ability is large, the decentralized architecture entails more tiers, less jurisdictions per tier with reduced scope of services than the centralized one, and the reverse if this relative weight is small. We use our results to estimate this weight on U.S. data. We find that the country exhibits two zones ("Northeast & West" and "Midwest & South") where the estimated values are statistically different.

Biotic factors such as pests create biodiversity effects that increase food production risks and decrease productivity when agriculture specializes. Under free trade, they reduce the specialization in food production that otherwise prevails in a Ricardian two-country setup. Pesticides allow farmers to reduce biodiversity effects , but they are damaging for the environment and for human health. When regulating farming practices under free trade, governments face a trade-off: they are tempted to restrict the use of pesticides compared to under autarky because domestic consumption partly relies on imports and thus depends less on them, but they also want to preserve the competitiveness of their agricultural sector on international markets. Contrary to the environmental race-to-the-bottom tenet, we show that at the symmetric equilibrium under free trade restrictions on pesticides are generally more stringent than under autarky. As a result, trade increases the price volatility of crops produced by both countries, and, depending on the intensity of the biodiversity effects, of some or all of the crops that are country-specific.

We analyze the adoption of green technology in a dynamic economy affected by random shocks where demand spillovers are the main driver of technological improvements. Firms' beliefs and consumers' anticipations drive the path of the economy. We derive the optimal policy of investment subsidy and the expected time and likelihood of reaching a targeted level of environmental quality under economic uncertainty. This allows us to estimate the value that should be given to the environment in order to avoid an environmental catastrophe as a function of the strength of spillover effects.

No summary available.

The strong increase in agricultural yields observed throughout the last 150 years is largely due to the improvement of varieties, which is itself essentially the result of research and development processes. The social optimality of the research effort undertaken by firms in this sector, as well as of the institutions framing the research activity, is an important issue for public policy. The purpose of this thesis is to contribute to shedding light on this issue, by attempting to take into account the environmental impact of innovation in agricultural varieties. We examine this topic through three different prisms: that of the innovation as such, that of the research process, and that of the institutional framework offered to research firms. We show that taking into account the environmental effects of research changes the optima of research, and should therefore lead to an adaptation of the incentive and regulatory framework.

Economic losses from natural disasters have increased globally faster than GDP over the past 30 years due to population growth and low levels of prevention in exposed regions. Moreover, only one third of these losses are insured and the low penetration of insurance generates wealth shocks for the affected populations. In this context and in the perspective of climate change, reducing natural disaster losses and increasing insurance coverage have become major issues for our societies, which are addressed in this thesis. The low levels of prevention and insurance can be explained by numerous market imperfections and deficient public policies, as explained in the introductory chapter of the thesis. A better understanding of these market problems and the role of public policy is needed to improve them. Chapter 2 focuses on prevention choices in the context of city development. Using an urban economics model, it shows that riskier areas are developed near the city center than far from the city center, investment in building resilience develops more concentrated cities, and riskier areas are less densely populated and generate more prevention. Furthermore, insurance subsidies lead to excessive exposure to risk through increased density in the riskiest areas and an overall decrease in resilience. This analysis illustrates the negative effects of subsidies and the role that urban public policies such as density restrictions or building codes can play. The following chapters address the issue of risk sharing in the context of risk correlation, a major feature of natural disaster risk. Using an economic model with potentially correlated individual risks, Chapter 3 demonstrates that a Pareto-optimal risk allocation can be achieved with competing insurance companies and a limited number of financial assets. This result, which is valid without market imperfections, requires in particular that agents are fully liable for the contracts signed in each state of nature. In practice, to limit defaults in catastrophic states, public policy requires that agents have financial reserves. Chapters 4 and 5 focus on the problem of risk correlation when these reserves are costly. Chapter 4 studies how the probability of a risk affects the choice of coverage of exposed individuals. It shows that individuals are more likely to insure for low probabilities than for high probabilities with standard insurance costs, but that the result is reversed when costs due to financial reserves are added. Chapter 5 analyzes the optimal form of insurance contracts when individual risks are correlated in a community. It shows that the optimal contract consists of partial insurance against individual risk, with lower coverage in catastrophic states than in normal states, plus potentially dividends in normal states. The final chapter concludes by opening up new research questions related to disaster prevention and insurance.

We examine the importance of production risks in agriculture due to biotic elements such as pests in determining the pattern of trade and the distribution of prices in a Ricardian two-country setup. These elements create biodiversity eff ects that result in an incomplete specialization at the free trade equilibrium. Their influence on idiosyncratic production risks evolves depending on the countries' openness to trade. Pesticides allow these eff ects to diminish but they are damaging for the environment and human health. When regulating farming practices, governments have to counterbalance these side-eff ects with the competitiveness of their agricultural sector on international markets. Nevertheless, restrictions on pesticides under free trade are generally more stringent than under autarky.

Production risks in agriculture due to biotic elements such as pests create biodiversity effects that impede productivity. Pesticides reduce these effects but are damaging for the environment and human health. When regulating farming practices, governments weigh these side-effects against the competitiveness of their agriculture. In a Ricardian two-country setup, we show that free trade results in an incomplete production specialization, that restrictions on pesticides are generally more stringent than under autarky and that trade increases the price volatility of crops produced by both countries and some of the specialized crops. If biodiversity effects are large, the price volatility of all crops is larger than under autarky.

Insurers have the reputation of being bad payers who nitpick whenever an opportunity arises. However, this nitpicking activity has a positive impact on their auditing strategy since auditing may prove profitable when claims are not fraudulent. We show that reducing the indemnity payments of audited claims induces a lower fraud rate at equilibrium and that some degree of nitpicking is socially optimal when insurance fraud is a concern. Its remains optimal even if it induces adverse effects on policyholders' moral standards.

The contingent claims analysis of firm financing often presents a debt renegotiation game with a passive bank that does not use its ability to force liquidation strategically, contrary to what is observed in practice. We consider two motives that may lead a bank to refuse to renegotiate: maintaining its reputation to preserve its future lending activity and deterring firms from overstating their debt service abatement when they renegotiate. We show that with public information and private debt only, the optimal probability of debt renegotiation is high when the firm's anticipated liquidation value is high. Under asymmetric information about liquidation value, the high liquidation value firm may be tempted to mimic the low liquidation value firm to reduce its debt service. To deter such mimicking, banks may sometimes refuse to renegotiate with firms having a low liquidation value.

In French: Cette thèse propose une analyse des politiques de stabilisation des prix alimentaires dans les pays pauvres. In order to represent the situation in these countries, we consider in a rational expectations storage model that consumers cannot insure themselves against price risk and that they are risk averse. The market incompleteness justifies public intervention and optimal stabilization policies are analyzed. An optimal public storage policy involves an increase in the level of storage. This additional storage leads to the crowding out of all private storers by eliminating speculative profit opportunities. Since the use of complex public intervention rules is unlikely in poor countries, we compare optimal food storage policies to simple rules such as a subsidy to private storage or a price band defended by public storage. Government involvement leads to welfare gains relative to a discretionary policy due to the possibility of manipulating producers' expectations and thus inducing them to stabilize prices. Simple stabilization rules allow for gains close to those obtained with optimal policies. In an open economy, the stabilization instruments are trade policy and storage. A storage policy unaccompanied by a trade policy does not benefit consumers, because the benefits of stabilization dissipate on the world market. On the contrary, an optimal trade policy increases stabilization by exploiting the world market.

No summary available.

The purpose of this thesis is to study the financial structure of LBOs and its impact on incentives to invest in the presence of informational asymmetry. The first chapter presents a statistical overview of the American, European and French LBO markets. We present the factors and sources of risk in these deals. The second chapter presents a review of the literature on leverage. This literature suggests that debt reduces the divergence of interests between shareholders and management and between shareholders and creditors, takes advantage of tax savings, improves the target's performance and signals its quality in the presence of asymmetric information in the market. However, it can also induce wealth transfers. The third chapter proposes a static double moral hazard model. The presence of the bank induces both agents to make optimal efforts under the condition of decreasing bank payments of income. By considering non-decreasing bank payments the model explains that in the absence of tax, the effort incentives of the entrepreneur and the LBO fund do not depend on the financial structure of the capital. We show that the deduction of debt interest creates an additional success income to be shared between the two agents, which induces them to increase their effort. In the fourth chapter, we study an extension to a dynamic setting of the previous model where the LBO fund can abandon 1 project of the entrepreneur. In case of premature exit, it has to pay compensation. The threat of abandonment induces both agents to increase their efforts. When the amount of the indemnities is exogenous, their distribution depends on the quality of the competing project: if the latter is not very profitable, they are shared between the entrepreneur and the bank. If the project is not very profitable, they are paid in full to the entrepreneur. When the amount of compensation is endogenous, both agents make greater efforts, only the entrepreneur is compensated.

Biofuels are developing rapidly in many countries thanks to government support, which is a necessary condition for their production. Thus, this thesis aims to study the regulation of biofuel support policies. More specifically, this work aims to shed light on the close links between biofuel policies and agricultural policies. Biofuel policies have evolved drastically over the last 3 years, moving from being a policy subordinate to agricultural policy to a central position at the crossroads of agricultural, environmental and energy policies. The work presented in this thesis is organized into three parts. First, we present the reasons behind the rapid development of biofuels. Then, in a second part, the interactions of biofuel policies with current agricultural policies are examined. This second part aims to assess the necessary changes in current policies to take into account the growing importance of energy crops in total agricultural production. Finally, a third part focuses on a new theoretical framework for the regulation of the agricultural sector, whose production is dual (it produces both a "classical" agricultural good and an environmental good): the Common Agency theory is used for this modeling. Thus, the common thread of the ideas developed in this thesis is the study of the interactions between biofuel policies and agricultural policies. Biofuels appeared during a reform of the CAP in 1992, are now central actors of the current CAP and will undoubtedly represent a key aspect of future agricultural policy reforms.

The purpose of this thesis is to study the regulatory instruments available to the European Union (EU), and more generally to a government, to achieve its objectives in the agricultural sector. The partial framework of analysis. The focus is on recent developments in this theory, and in particular the modeling of incentive mechanisms, which are very well suited to contractual policies and tendering systems. Two instruments used by the EU, which more specifically concern the production and marketing of cereals, are thus analyzed: a policy of restricting supply through the land input, commonly called "set-aside", and "export refunds", which are systems of aid to exports that operate, in part, through tendering. The traditional theory of welfare is the subject of the first part. Recent developments in this theory as applied to the agricultural sector of developed economies are presented. The theory of mechanisms is then presented. This second part deals in particular with the mixed problems of asymmetric information, mixing anti-selection and moral hazard, which correspond to the general case of regulation by production. We are particularly interested in the properties of threshold mechanisms. The last part of this thesis is more specifically devoted to the study of two European agricultural policies. The first is a contractual policy of supply control through input, adopted at the end of the 1980s. The second concerns the sale of grain stocks that the community builds up through its intervention in the market.