Hotelling tax competition

This paper shows how competition among governments for mobile firms can bring about excessive differentiation in levels of taxation and public good provision. Hotelling’s Principle of Minimum Differentiation is applied in the context of tax competition and shown to be invalid. Instead, when an equilibrium exists, differentiation of public good provision is maximized. Non-existence of equilibrium, which can occur, is a metaphor for intense tax competition. The paper also shows that, to some extent, perfect tax discrimination presents a solution to the existence problem created by Hotelling tax competition, but that the efficiency problem of Hotelling tax competition is exacerbated

The efficiency, equity and politics of emissions permit trading

This paper illustrates that an international permit trading system may hurt relatively poor countries by making associated economic activities unaffordable. A model is constructed in which the free market solution is Pareto inefficient as a result of pollution. The introduction of tradable permits allows pollution to be internalised, and brings about an increase in the total social surplus. But when incomes vary, this may not lead to a Pareto improvement; those in poor countries stop the polluting activity because they cannot afford to do otherwise. Only those in relatively rich countries are made better off. This may explain why poor countries are reluctant to ratify the Kyoto Protocol, itself advocating a permit trading scheme. The politico-economic implications of permit trading are also examined. We show that the democratic requirements for ratification impose a lower bound on pollution reduction that can be achieved through a system of pollution permits with trade

Tax competition reconsidered

In a classic model of tax competition, we show that the level of public good provision and taxation in a Nash equilibrium can be efficient or inefficient with either too much, or too little public good provision. The key is whether there exists a unilateral incentive to deviate from the efficient state and, if so, whether this entails raising or lowering taxes. A priori, there is no reason to suppose the incentive is in either one direction or the other. In addition, we demonstrate conditions ensuring existence of an asymmetric Nash equilibrium with efficient public good provision. As in prior literature, local amenities enhance capital’s productivity. Prior literature, however, focuses on under-provision of public goods

Relaxing tax competition through public good differentiation

This paper argues that, because governments are able to relax tax competition through public good differentiation, traditionally high-tax countries have continued to set taxes at a relatively high rate even as markets have become more integrated. The key assumption is that firms vary in the extent to which public good provision reduces costs. We show that Leviathan governments are able to use this fact to relax the forces of tax competition, reducing efficiency. When firms can ‘vote with their feet’ tax competition leads firms to locate in ‘too many’ jurisdictions. A ‘minimum tax’ further relaxes tax competition, further reducing efficiency

Impfverhalten, Lebensqualität und Behinderung nach Guillain-Barré-Syndrom

Das Guillain-Barré-Syndrom (GBS) ist eine akute Entzündung des peripheren Nervensystems. Es zeigt sich in symmetrisch aufsteigenden Lähmungen. Auslöser für ein GBS sind beispielsweise bestimmte Erreger oder die 1976/77er Impfung gegen die Influenza A/H1N1. Ziel dieser Studie war es, die Einstellung ehemaliger GBS-Patienten zu Impfungen zu ermitteln sowie Daten zu ihrem Gesundheitszustand zu sammeln. Dazu wurde ein Fragebogen aus dem Short-Form-36 Gesundheitsfragebogen (SF-36), der Overall Neuropathy Limitations Scale (ONLS) und Fragen zu Impfungen erstellt und an Empfänger eines GBS-Magazins sowie GBS-Patienten des Universitätsklinikums Jena geschickt. Insgesamt konnten die Antworten von 123 Patienten eingeschlossen werden. 78,9 % gaben als Diagnose GBS an, 21,1 % chronische inflammatorische demyelinisierende Neuropathie (CIDP), eine chronische Form des GBS. Die Teilnehmer waren im Durchschnitt 67 Jahre alt, 63,4 % waren männlich, 35,0 % weiblich. Der Gesundheitszustand der Patienten war im SF-36 in allen acht Domänen schlechter als der einer deutschen Normstichprobe. In der ONLS zeigten 80 % der Befragten neuropathische Restsymptome. Im Vergleich zur Normalbevölkerung waren die Befragten kritischer zu Impfungen eingestellt und ließen sich seltener impfen. Knapp 10 % gaben an, zu glauben, dass ihre Erkrankung durch eine Impfung ausgelöst wurde. Häufigste Gründe gegen eine Impfung waren Angst vor den Nebenwirkungen und das Abraten eines Arztes. Nach Erkrankung ließen sich 20 % weniger impfen als davor. 40 % befürchteten, dass eine Impfung ein erneutes GBS auslösen könnte. Impfungen gelten für GBS-Patienten als sicher. Es gilt somit, Aufklärungsarbeit zu leisten, um die genannten Sorgen bezüglich Impfungen sowohl auf Seiten der Patienten als auch auf Seiten des medizinischen Personals auszuräumen. In der Langzeitversorgung von GBS-Patienten gilt zu beachten, dass ein Großteil auch Jahre nach Erkrankung noch unter Restsymptomen und Einschränkungen leidet

Using Logs Data to Identify When Software Engineers Experience Flow or Focused Work

Beyond self-report data, we lack reliable and non-intrusive methods for identifying flow. However, taking a step back and acknowledging that flow occurs during periods of focus gives us the opportunity to make progress towards measuring flow by isolating focused work. Here, we take a mixed-methods approach to design a logs-based metric that leverages machine learning and a comprehensive collection of logs data to identify periods of related actions (indicating focus), and validate this metric against self-reported time in focus or flow using diary data and quarterly survey data. Our results indicate that we can determine when software engineers at a large technology company experience focused work which includes instances of flow. This metric speaks to engineering work, but can be leveraged in other domains to non-disruptively measure when people experience focus. Future research can build upon this work to identify signals associated with other facets of flow

Stimuli-responsive 2D polyelectrolyte photonic crystals for optically encoded pH sensing.

A versatile photonic crystal sensing motif based on a twodimensional (2D) inverse opal monolayer of stimuli-responsive polyelectrolyte gel with tunable optical properties is reported. The photonic membrane shows prompt response to pH and can be readily read out from either its optical spectra or interference colours

Zonotopal algebra

A wealth of geometric and combinatorial properties of a given linear endomorphism $X$ of $\R^N$ is captured in the study of its associated zonotope $Z(X)$, and, by duality, its associated hyperplane arrangement ${\cal H}(X)$. This well-known line of study is particularly interesting in case n\eqbd\rank X \ll N. We enhance this study to an algebraic level, and associate $X$ with three algebraic structures, referred herein as {\it external, central, and internal.} Each algebraic structure is given in terms of a pair of homogeneous polynomial ideals in $n$ variables that are dual to each other: one encodes properties of the arrangement ${\cal H}(X)$, while the other encodes by duality properties of the zonotope $Z(X)$. The algebraic structures are defined purely in terms of the combinatorial structure of $X$, but are subsequently proved to be equally obtainable by applying suitable algebro-analytic operations to either of $Z(X)$ or ${\cal H}(X)$. The theory is universal in the sense that it requires no assumptions on the map $X$ (the only exception being that the algebro-analytic operations on $Z(X)$ yield sought-for results only in case $X$ is unimodular), and provides new tools that can be used in enumerative combinatorics, graph theory, representation theory, polytope geometry, and approximation theory.Comment: 44 pages; updated to reflect referees' remarks and the developments in the area since the article first appeared on the arXi

Underreported Threat of Multidrug-Resistant Tuberculosis in Africa

Identification of population-based factors should influence regional and national policy

The Atacama Cosmology Telescope: Cosmology from Galaxy Clusters Detected via the Sunyaev-Zel'dovich Effect

We present constraints on cosmological parameters based on a sample of Sunyaev-Zel'dovich-selected galaxy clusters detected in a millimeter-wave survey by the Atacama Cosmology Telescope. The cluster sample used in this analysis consists of 9 optically-confirmed high-mass clusters comprising the high-significance end of the total cluster sample identified in 455 square degrees of sky surveyed during 2008 at 148 GHz. We focus on the most massive systems to reduce the degeneracy between unknown cluster astrophysics and cosmology derived from SZ surveys. We describe the scaling relation between cluster mass and SZ signal with a 4-parameter fit. Marginalizing over the values of the parameters in this fit with conservative priors gives sigma_8 = 0.851 +/- 0.115 and w = -1.14 +/- 0.35 for a spatially-flat wCDM cosmological model with WMAP 7-year priors on cosmological parameters. This gives a modest improvement in statistical uncertainty over WMAP 7-year constraints alone. Fixing the scaling relation between cluster mass and SZ signal to a fiducial relation obtained from numerical simulations and calibrated by X-ray observations, we find sigma_8 = 0.821 +/- 0.044 and w = -1.05 +/- 0.20. These results are consistent with constraints from WMAP 7 plus baryon acoustic oscillations plus type Ia supernoava which give sigma_8 = 0.802 +/- 0.038 and w = -0.98 +/- 0.053. A stacking analysis of the clusters in this sample compared to clusters simulated assuming the fiducial model also shows good agreement. These results suggest that, given the sample of clusters used here, both the astrophysics of massive clusters and the cosmological parameters derived from them are broadly consistent with current models.Comment: 12 pages, 7 figures. Submitted to Ap