Les consommateurs disposent d’une rationalité limitée et sont sujets à divers biais cognitifs. La thèse étudie les conséquences des biais de rationalité sur le comportement des consommateurs ainsi que les implications sur la politique de consommation. Chacun des trois chapitres de la thèse est consacré à un biais particulier (surestimation de la qualité, erreurs d’anticipation de l’utilité, biais de projection) dans un contexte concurrentiel déterminé. Les deux premiers chapitres sont bâtis sur des modèles de duopole standards auxquels sont intégrés des biais de rationalité : le premier est un duopole avec différenciation horizontale inspiré de Dixit (1979), tandis que le second envisage un modèle de différenciation verticale adapté de Gabszewicz & Thisse (1979). Le troisième chapitre étend à trois périodes la modélisation du biais de projection proposée par Loewenstein et al. (2003). J’aboutis à la conclusions que, si les biais cognitifs conduisent dans certains cas à des choix sous-optimaux (chapitres 1 et 2), les consommateurs naïfs peuvent également être avantagés par rapport aux agents sophistiqués (chapitre 3). Ce constat plaide en faveur d’une intervention circonstanciée et mesurée sur le marché. Enfin, des recommandations de politiques économiques sont formulées: je prône une approche renouvelée du droit de la consommation, qui ne serait plus fondé principalement sur l’information du consommateur mais davantage sur des mesures de redressement cognitif. Des exemples de mesures concrètes sont discutés tout au long de la thèse. / Consumers have bounded rationality and exhibit cognitive biases. The thesis studies the consequences of such biases on consumer choice and implications on consumer policy. Each chapter of the thesis investigates one specific bias (quality bias, utility misperception and projection bias) in a given market structure. The first two chapters focus on stan- dard duopoly models, in whichcognitive biases are incorporated: I build a horizontally differentiated duopoly based on Dixit (1979)in chapter 1, and a vertically differentiated duopoly inspired by Gabszewicz & Thisse (1979) in chapter 2. As for the third chapter, it extends to three periods, in a monopolistic framework, the projection bias model proposed by Loewenstein et al. (2003). I come to the conclusion that, while cognitive biases sometimes lead to suboptimal consumption decisions (chapters 1 and 2), naive consumers can be better off than their sophisticated counterparts(chapter 3). This observation pleads in favor of a non-systematic and context dependant legal intervention to counter cognitive errors. I argue in favor of a new approach of consumer policy, that would focus less on information disclosures in favor of debiasing schemes. Examples of such debiasing policies are discussed throughout the thesis.

The 1980 United Nations Convention on the International Sale of Goods, concluded under the auspices of UNCITRAL, creates a comprehensive statutory legal framework for international sales. Through the express incorporation of the principle of freedom of contract, the convention contains rules which the parties may freely adapt to the particular circumstances of their transaction, by filling any gaps that may arise with trade usages and other practices. In addition, the convention recognises the binding force of international trade usages in certain circumstances, in that it binds parties to usages which are so widely known and have acquired such regularity of observance in international trade as to justify an expectation that they will be observed in the particular transaction. Such acknowledgment of the changing patterns and norms of behaviour which characterise international trade law allows the CISG to be categorised as a major component of the modern lex mercatoria. / Constitutional International & Indigenous Law / LL.M.

The 1980 United Nations Convention on the International Sale of Goods, concluded under the auspices of UNCITRAL, creates a comprehensive statutory legal framework for international sales. Through the express incorporation of the principle of freedom of contract, the convention contains rules which the parties may freely adapt to the particular circumstances of their transaction, by filling any gaps that may arise with trade usages and other practices. In addition, the convention recognises the binding force of international trade usages in certain circumstances, in that it binds parties to usages which are so widely known and have acquired such regularity of observance in international trade as to justify an expectation that they will be observed in the particular transaction. Such acknowledgment of the changing patterns and norms of behaviour which characterise international trade law allows the CISG to be categorised as a major component of the modern lex mercatoria. / Constitutional International and Indigenous Law / LL.M.

Current traditional delivery models used in the Australian construction industry are seen as highly bespoke and adversarial where there is an inappropriate contractual risk allocation, lack of collaboration and poor project management. With the pipeline of investment compounded with the impact that global macroeconomic trends and events (e.g., COVID-19, climate change, political instability, social change, digital revolution) have on supply chains and risk profiles; there are calls from practitioners and researchers for fundamental change to contractual delivery arrangements to support the implementation of collaboration. The standard form of contract known as the New Engineering Contract (NEC) is seen as a logical step in the right direction; however, there is a lack of in-depth investigation to understand and support its implementation, particularly in Australia. This thesis aims to understand whether NEC could be utilised to a greater extent in the Australian construction industry by using institutional theory as a frame of reference. This paper reports on an exploratory interview study with a range of professionals in the construction industry in Australia to understand the current problems with traditional procurement, NEC’s perceived role and contribution to developing contractual practice, the barriers to change and the roles that various actors play in driving the development of NEC. The study confirms that the industry has a range of economic, knowledge-related and cultural factors that motivate the need for change. The effect of these practices has become part of the institution of the construction industry, ‘the way we do things. This has resulted in inefficient and poor performance outcomes. The general perception and experience amongst industry participants is seen as positive to NEC, where many acknowledge clear advantages but also various issues to its implementation. Key institutional actors are perceived to act as barriers to further adoption of NEC are the government, clients/public sector organisations and the legal profession. Other main barriers identified include the limited number of trained professionals and the culture and mindset in the industry. Greater adoption of NEC requires the active role of government, clients, and industry and professional bodies. / I den australiensiska byggindustrin används idag skräddarsydda kontrakt som skapar motsättningar mellan parterna genom obalanserad riskallokering och är förknippade med dåligt samarbete och bristande projektledning. Med tanke på den stora volymen planerade investeringar och den påverkan som globala makroekonomiska trender och händelser (t.ex. covid-19, klimatförändringar, politisk instabilitet, social förändring, digital omställning) har på leveranskedjor och riskprofiler, är det idag många praktiker och forskare som pekar på behovet av nya kontrakt som stödjer samverkan. Standardkontraktet New Engineering Contract (NEC) ses då som ett steg i rätt riktning. Syftet med detta examensarbete är att förstå de nuvarande problemen i den australiensiska byggindustrin och undersöka om NEC skulle kunna användas i större utsträckning. Studien baseras på intervjuer med yrkesverksamma inom byggbranschen i Australien. Med hjälp av institutionell teori diskuteras NEC:s upplevda roll och bidrag till att utveckla avtalspraxis, hindren för förändring samt de roller som olika aktörer spelar i att driva utvecklingen av NEC. Studien visar att branschen präglas av en rad ekonomiska, kunskapsrelaterade och kulturella faktorer som motiverar behovet av förändring. De har blivit en del av byggindustrins institutionaliserade praktiker, "så här gör vi", och har resulterat i ineffektivitet och kvalitetsbrister. De intervjuade är generellt positiva till NEC, men ser både tydliga fördelar och vissa problem med det. Centrala institutionella aktörer som idag fungerar som hinder för fortsatt implementering är statliga myndigheter, andra offentliga byggherrar och den juridiska professionen. Andra barriärer som identifierats är bristen på yrkesverksamma som är utbildade i NEC samt branschens kultur och tänkesätt. En ökad användning av NEC förutsätter en aktiv roll från myndigheter, kunder, branschorgan och professionsföreningar.