Tax Evasion and Social Interactions

The paper extends the standard tax evasion model by allowing for social interactions. In Manski's (1993) nomenclature, our model takes into account social conformity effects (i.e., endogenous interactions), fairness effects (i.e., exogenous interactions) and sorting effects (i.e., correlated effects). Our model is tested using experimental data. Participants must decide how much income to report given their tax rate and audit probability, and given those faced by the other members of their group as well as their mean reported income. The estimation is based on a two-limit simultaneous tobit with fixed group effects. A unique social equilibrium exists when the model satisfies coherency conditions. In line with Brock and Durlauf (2001b), the intrinsic nonlinearity between individual and group responses is sufficient to identify the model without imposing any exclusion restrictions. Our results are consistent with fairness effects but reject social conformity and correlated effects.social interactions; tax evasion; simultaneous tobit; laboratory experiments

Tax Evasion and Social Interactions

The paper extends the standard tax evasion model by allowing for social interactions. In Manski's (1993) nomenclature, our model takes into account social conformity effects (i.e., endogenous interactions), fairness effects (i.e., exogenous interactions) and sorting effects (i.e., correlated effects). Our model is tested using experimental data. Participants must decide how much income to report given their tax rate and audit probability, and given those faced by the other members of their group as well as their mean reported income. The estimation is based on a two-limit simultaneous tobit with fixed group effects. A unique social equilibrium exists when the model satisfies coherency conditions. In line with Brock and Durlauf (2001b), the intrinsic nonlinearity between individual and group responses is sufficient to identify the model without imposing any exclusion restrictions. Our results are consistent with fairness effects but reject social conformity and correlated effects.laboratory experiments; simultaneous Tobit; social interactions; tax evasion

Tax Evasion and Social Interactions

The paper extends the standard tax evasion model by allowing for social interactions. In Manski's (1993) nomenclature, our model takes into account social conformity effects (i.e., endogenous interactions), fairness effects (i.e., exogenous interactions) and sorting effects (i.e., correlated effects). Our model is tested using experimental data. Participants must decide how much income to report given their tax rate and audit probability, and given those faced by the other members of their group as well as their mean reported income. The estimation is based on a two-limit simultaneous tobit with fixed group effects. A unique social equilibrium exists when the model satisfies coherency conditions. In line with Brock and Durlauf (2001b), the intrinsic nonlinearity between individual and group responses is sufficient to identify the model without imposing any exclusion restrictions. Our results are consistent with fairness effects but reject social conformity and correlated effects.Social interactions, tax evasion, simultaneous tobit, laboratory experiments

Tax Evasion and Social Interactions

The paper extends the standard tax evasion model by allowing for social interactions. In Manski's (1993) nomenclature, our model takes into account endogenous interactions, i.e., social conformity effects, exogenous interactions, i.e., fairness effects, and correlated effects. Our model is tested using experimental data. Participants must decide how much income to report given individual and group tax rates and audit probabilities, and given a feedback on theother members' reporting behavior. Myopic and self-consistent expectations are considered in the analysis. In the latter case, the estimation is based on a two-limit simultaneous tobit with fixed group effects. A unique social equilibrium exists when the model satisfies coherency conditions. In line with Brock and Durlauf (2001b), the intrinsic nonlinearity between individual and group responses helps identify the model. Our results provide evidence of fairness effects but reject social conformity.laboratory experiments; simultaneous Tobit; social interactions; tax evasion

La modélisation pragmatiste de l'action didactique de l'enseignant comme théorie ancrée.: Analyses de cas relatifs à des séances de sciences s'appuyant sur des démarches d'investigation avec utilisation de documents vidéo.

International audienceLes didacticiens ont investi le domaine de l'enseignement par démarche d'investigation en sciences selon différentes options de recherche, liées aux objectifs qu'ils se fixent : propositions de séances, ingénieries didactiques en co-élaboration, analyses de pratiques (voir par exemple, Calmettes, 2012a ; Grangeat, 2013). À l'issue de ces études, un certain nombre de constats peuvent être posés :-Il existe une certaine variabilité dans les modalités de préparation (Bécu-Robinaut, 2007) et dans les mises en oeuvre des séances (Calmettes, 2009 ; Grangeat, 2013).-Lorsque les chercheurs analysent les séances, d'un point de vue externe, ils repèrent des écarts entre les perspectives apparamment ouvertes par les démarches d'investigation en termes épistémologiques et constructivistes, les discours généraux des enseignants à propos de ces démarches et ce qu'ils font dans les classes (Calmettes & al., 2008).Pour tenter d'avancer dans la compréhension de l'action didactique de l'enseignant en classe ordinaire, nous avons proposé récemment une nouvelle approche théorique didactique en nous appuyant notamment sur des idées et des principes issus de la philosophie et de la sociologie : la modélisation pragmatiste de l'action didactique de l'enseignant (Calmettes, 2010). L'objectif de cette communication est, d'abord de présenter le cadre général de construction de cette approche, ensuite de décrire rapidement les concepts qui y sont développés, enfin d'illustrer le travail visant à la faire évoluer, à partir d'études monographiques, dans de nouveaux contextes

Diffusive model of current-in-plane-tunneling in double magnetic tunnel junctions

We propose a model that describes current-in-plane tunneling transport in double barrier magnetic tunnel junctions in diffusive regime. Our study shows that specific features appear in double junctions that are described by introducing two typical length scales. The model may be used to measure the magnetoresistance and the resistance area product of both barriers in unpatterned stacks of double barrier magnetic tunnel junctions.Comment: 4 pages, 3 figure