Tax evasion, information reporting, and the regressive bias hypothesis

A robust prediction from the tax evasion literature is that optimal auditing induces a regressive bias in e¤ective tax rates compared to statutory rates. If correct, this will have important distributional consequences. Nevertheless, the regressive bias hypothesis has never been tested empirically. Using a unique data set, we provide evidence in favor of the regressive bias prediction but only when controlling for the tax agency�s use of third-party information in predicting true incomes. In aggregate data, the regressive bias vanishes because of the systematic use of third-party information. These results are obtained both in simple reduced-form regressions and in a data-calibrated state-of-the-art model

The Effects of DRO and DRA for Increasing Academic Engagement and Decreasing Disruptive Behavior of Elementary Students in General Education Classrooms

The research literature suggests that functional assessment and differential reinforcement methods are effective for decreasing an array of problem behaviors. However, research is limited in the number of studies including children of typical development exhibiting common problem behaviors (e.g., inappropriate vocalization, off-task behavior) in a general education setting. In addition, previous studies have failed to report data regarding increases in appropriate replacement behaviors. The purpose of the present study was to examine the relative effectiveness of differential reinforcement of other behavior (DRO) and differential reinforcement on alternative behavior (DRA) for decreasing problem behavior and increasing academically engaged behavior with elementary-age students of typical development in a general education setting. Participants included two elementary-age students receiving general education instruction. Following a functional behavior assessment, the relative effectiveness of DRO and DRA was evaluated using an alternating treatments design (ATD). Results suggest that both DRO and DRA are effective for decreasing problem behavior and increasing academic engagement, with DRO being more effective for one participant and DRA being more effective for the other

The Effects of Function-Based Antecedent and Consequent Interventions for Increasing Appropriate Behavior and Decreasing Disruptive Behavior of Preschool Students in the School Setting

The Functional Behavior Assessment (FBA) literature suggests that functionbased interventions are effective at improving problem behavior for individuals in a variety of settings. However, the FBA literature is limited in the number of studies that examine the relative effectiveness of function-based antecedent and consequent interventions for reducing problem behavior and increasing appropriate replacement behaviors. Additionally, while there has been a recent increase in the number of studies conducted in the school setting, only a limited number of studies include children in the preschool setting. The purpose of the present study was to extend the literature by examining the relative effectiveness of function-based antecedent and consequent interventions for reducing problem behavior and increasing appropriate replacement behavior for preschool children of typical development. The following study included four preschool-age children. Following a functional behavior assessment, the relative effectiveness of a function-based antecedent and consequent intervention was examined using an alternating treatments design (ATD). Results indicate that both the function based antecedent intervention and consequent intervention were effective at decreasing problem behavior and increasing appropriately engaged behavior, with the function-based antecedent intervention being more effective than the function-based consequent intervention for two of the four participants

The Bianchi Ix (MIXMASTER) Cosmological Model is Not Integrable

The perturbation of an exact solution exhibits a movable transcendental essential singularity, thus proving the nonintegrability. Then, all possible exact particular solutions which may be written in closed form are isolated with the perturbative Painlev\'e test; this proves the inexistence of any vacuum solution other than the three known ones.Comment: 14 pages, no figure

On the 7th order ODE with submaximal symmetry

We find a general solution to the unique 7th order ODE admitting ten dimensional group of contact symmetries. The integral curves of this ODE are rational contact curves in \PP^3 which give rise to rational plane curves of degree six. The moduli space of these curves is a real form of the homogeneous space $Sp(4)/SL(2)$.Comment: 6 pages, 2 figures. Final version - to appear in JG

Ricci flows and expansion in axion-dilaton cosmology

We study renormalization-group flows by deforming a class of conformal sigma-models. We consider overall scale factor perturbation of Einstein spaces as well as more general anisotropic deformations of three-spheres. At leading order in alpha, renormalization-group equations turn out to be Ricci flows. In the three-sphere background, the latter is the Halphen system, which is exactly solvable in terms of modular forms. We also analyze time-dependent deformations of these systems supplemented with an extra time coordinate and time-dependent dilaton. In some regimes time evolution is identified with renormalization-group flow and time coordinate can appear as Liouville field. The resulting space-time interpretation is that of a homogeneous isotropic Friedmann-Robertson-Walker universe in axion-dilaton cosmology. We find as general behaviour the superposition of a big-bang (polynomial) expansion with a finite number of oscillations at early times. Any initial anisotropy disappears during the evolution.Comment: 22 page

A time-extended Hamiltonian formalism

A Poisson structure on the time-extended space R x M is shown to be appropriate for a Hamiltonian formalism in which time is no more a privileged variable and no a priori geometry is assumed on the space M of motions. Possible geometries induced on the spatial domain M are investigated. An abstract representation space for sl(2,R) algebra with a concrete physical realization by the Darboux-Halphen system is considered for demonstration. The Poisson bi-vector on R x M is shown to possess two intrinsic infinitesimal automorphisms one of which is known as the modular or curl vector field. Anchored to these two, an infinite hierarchy of automorphisms can be generated. Implications on the symmetry structure of Hamiltonian dynamical systems are discussed. As a generalization of the isomorphism between contact flows and their symplectifications, the relation between Hamiltonian flows on R x M and infinitesimal motions on M preserving a geometric structure therein is demonstrated for volume preserving diffeomorphisms in connection with three-dimensional motion of an incompressible fluid.Comment: 14 pages, late