Quality signalling in motion picture markets is hardly a new topic. It has been covered by many researchers over the years. However, most of the previous studies focused on quality signals in interactions between moviemakers and moviegoers. This study employs a more holistic approach as the author attempts to evaluate effects of quality signals throughout different stages of movies’ life cycle. The author has identified three audiences that movies are presented to; and, each group of audience generates a quality signal for the next audience. Based on the feedback from test audiences, moviemakers decide on when to show movies to professional critics and when to allow them to publish their reviews. Interpretation of these timelines become quality signals for the professional critics who interpret shorter time slot for review publication as a signal of the low quality of the movie and vice versa. Professional critics write their reviews which when published on review aggregators become quality signals for the moviegoers. Reviews generated by the initial moviegoers are interpreted by the moviegoers who intend to watch movies at a later stage. All three assumptions are operationalised and evaluated in a series of linear regression tests in this research on a sample containing 130 out of 134 widely released movies in the US and Canada domestic market in 2017. All of the abovementioned quality signals found to be significant as they could explain at least 40 % of the variance of respective response variables.

Cette thèse s’intéresse aux certifications avec « label », chartes et systèmes participatifs de l’économie solidaire, ou « dispositifs de qualité ». Elle contribue à l’analyse sociologique de ces dispositifs, dans un secteur qui connaît leur multiplication et leur diversification depuis les années 1990. L’enquête repose sur des entretiens au sein de douze réseaux (commerce équitable, AMAP, SEL…), des observations, l’analyse de documents et la passation d’un questionnaire. La genèse des dispositifs met en évidence leur rôle dans la construction d’une identité collective. Leur fonctionnement soulève des enjeux démocratiques. Les représentations de la confiance et de la qualité qui les sous-tendent révèlent le positionnement des collectifs vis-à-vis de la production standard et les uns par rapport aux autres. Leurs usages économiques et identitaires s’inscrivent dans la démarche contestataire des membres les plus actifs. L’hétérogénéité entre les attentes de ces derniers et celles des autres adhérents concourt aux difficultés liées à l’instauration des dispositifs de qualité. Ceux-ci ne sont pas uniquement destinés à l’orientation des acheteurs mais également à la promotion, par des producteurs engagés, de valeurs se voulant alternatives à celles de l’économie classique. / This thesis focuses on solidarity economy’s certification labels, charters and participatory systems, as “quality devices”. It contributes to the sociological analysis of these devices, in a sector in which they are increasing in number and have become more diverse since the 1990’s. This investigation relies on interviews in twelve networks (fair-trade, community-supported agriculture, LETS…), observations, document analysis and the administration of a questionnaire.The history of these measures accounts for the role they play in the construction of a collective identity. The way they operate raises democratic issues. Their underlying representations of confidence and quality reveal the positioning of these networks on standard production and in relation to each other. Their uses as economic and identity-shaping tools need to be viewed as part of a protest strategy adopted by the networks’ most active members. Differences in expectations among network members give rise to difficulty in implementing quality measures. They are not only intended to help buyers but also created by committed producers in order to promote values they consider as “alternative” in regards to classical economy.