Cette thèse cherche à étudier les liens existants entre les contrats formels et les comportements coopératifs. Les contrats formels étant censés faciliter la collaboration et éviter des incompréhensions coûteuses entre les parties, nous nous intéressons dans un premier temps à la manière dont le contrat formel impacte sur la capacité des parties à coopérer. Nous analysons ensuite, dans un même ordre d’idée, la coopération à travers le prisme des renégociations contractuelles. L’objectif est alors d’étudier la façon dont les contrats s’adaptent à un environnement changeant à travers le temps. Enfin, l’étude se porte sur l’impact de l’existence de rapports informels, considérés par la littérature antérieure comme, de manière alternative, substitut ou complément aux contrats formels. Plus précisément, nous étudions comment l’existence de mécanismes relationnels influe sur les choix contractuels. Ainsi, l’objectif est d’améliorer la compréhension du rôle joué par les contrats formels et la coopération informelle dans les relations et d’enrichir la théorie sur les déterminants de l’incomplétude contractuelle. Nos résultats suggèrent que le rôle du contrat formel dans les relations dépend fortement du contexte et de l’identité des parties concernées. Nos résultats permettent également d’identifier la capacité des parties à soutenir un accord relationnel comme une nouvelle source endogène d’incomplétude contractuelle. Enfin, nous obtenons également que les adaptations contractuelles, par le biais des renégociations, ne sont pas nécessairement nocives pour les parties. Au final, nous pensons que cette thèse contribue à la littérature sur le débat entre complémentarité et / ou substituabilité des modes de gouvernance formels et informels ainsi qu’à la littérature sur le lien entre contrat relationnel et l’incomplétude contractuelle endogène. Par conséquent, l’implication majeure de ce travail de thèse est illustrée par la nécessité pour les parties de réfléchir attentivement au contrat initial et aux efforts consentis pour sa rédaction. En premier lieu car le contrat formel impacte sur leur capacité à coopérer ex post et, en second lieu, car le contrat formel peut se révéler être trop complet par rapport au niveau de complétude optimal. / This Ph.D. dissertation seeks to investigate the existing links between cooperative behavior and formal contracts. First, because formal agreements are supposed to facilitate smooth collaboration and avoid costly misunderstandings, we are interested in how formal contracts impact on the ability of parties to cooperate. Following the same intuition, we also analyze cooperation through the lens of renegotiations in order to investigate how contracts adapt themselves through time in a changing environment. Second, we also study the impact of the existence of informal dealings, alternatively considered in previous literature as substitute or complement to formal contracting. More precisely, we aim to investigate how the existence of relational mechanisms may impact on contractual choices. Our goal is thus to improve the understandings of the role played by formal contract and informal cooperation in relationships and to enrich the theory of the determinants of incomplete contract. Our results suggest that the role of formal contract in relationships strongly depends on the context and the identity of parties. Our results also identify the ability of the parties to sustain a relational agreement as a new source of endogenous contractual incompleteness. Finally, we also find that adaptations through contractual renegotiations are not necessarily harmful for the contracting parties. We believe that this Ph.D. dissertation contributes to the literature on the debate of complementarity and/or the substitutability of formal and informal governance and to the literature on the link between relational contract and endogenous contractual completeness. In the end, the overall implication is the necessity for parties to carefully think about the initial contract they draft. Because it has an impact on their ability to cooperate ex post and also because contracts can be over-complete compared to the efficient (i.e. socially optimal) level of completeness.

Abstract R&D investment differs from general investments due to more and greater uncertainties. Once the R&D technique is selected and the investment turns into sunk cost, a path dependence of the R&D investment will occur that locks in the involved parties in the R&D cooperation relationship and the determined cost path. Due to information asymmetry, whether the executer honestly provides information about the project type will be critical to the profit or loss of the R&D investment. If a high cost type project be confesses, the financier can immediately terminate the project to avoid more losses. On the contrary, if the cost type is concealed, the financier will sink more costs into it. Thus, soft budget constraint should be seriously considered in R&D investments. First, we capture the intrinsic uncertainty in R&D investment by introducing both cost and outcome uncertainties of R&D investment. Furthermore, we introduce the financier type and the executor¡¦s expectation of the probability that a high cost project would be refinanced ex post to establish a dynamic game of incomplete information. With this setup, we develop reputation effects from repeated R&D games. The incentive for the financier to avoid executor¡¦s opportunism by establishing reputation makes the commitment to hard budget constraint credible. Second, we attempt to develop a foundation for the concept of the SBC and to extend the analysis of SBCs to the contractual relationship of R&D investment. Information asymmetry is one important cause for contractual incompleteness, and the only one cause makes two legal contract theories unhelpful. Instead of relying on court enforcement, it is possible for the financier to leave contract terms unspecified and rely on a private self-enforcement mechanism. Writing down explicit contract terms can define the self-enforcing range by imposing a private sanction on the executer perceived to be violating the contract understanding. Such a self-enforcing relationship is a useful framework in which to analyze the SBC of R&D investment. In Chapter 5, we describe industrial R&D activities in China and uses statistics to calculate the softness of budget constraint. The main point of the R&D investment model is that the incentive for the financier to establish reputation increases as the probability of success decreases. With this point of view, given the probability of success for R&D projects in high-tech industries being lower than that in conventional industries, refinancing should be relatively more common in conventional industries than in high-tech industries. Statistics of R&D activities in China confirm the above proposition in that the computer-related industry has the hardest budget constraint compared to other industries within the state-controlled sector.