Local sales taxes can reduce the differences between taxes at state borders

Local sales taxes are an important source of revenue for municipalities and counties in over thirty states. How do municipalities set local sales taxes? Studying the sales tax differentials between high and low sales tax states, David R. Agrawal finds that local jurisdictions in low-tax states set higher local sales tax rates than jurisdictions on the other side of the border in the high-tax state. In addition, jurisdictions far inside low-tax states set lower tax rates compared to border towns

Fiscal Decentralisation and Mobility: Evidence from Spain's Income Tax System

In recent decades, many countries around the world have become more fiscally decentralised. Spain provides a unique case study given it has relatively quickly transitioned from a highly centralised country to a much more decentralised country, although formally not a federation. As part of this decentralisation, autonomy over individual income tax rates and brackets was recently granted to the regions (Autonomous Communities), which are similar to states or provinces in other countries. In the early 2000s, individual income tax brackets and rates were the purview of the central government. Only recently were the Spanish regions granted the authority to levy their own individual income tax rates on a portion of the personal income tax base. Once granted this authority, marginal tax rates diverged substantially at the top of the income distribution, resulting in substantial tax differentials across various regions within Spain. This article reviews the economic consequences of Spanish fiscal decentralisation with a particular focus on the impact on the mobility of high-income individuals and the implications of migration decisions for public finances

Fiscal Decentralisation and Mobility: Evidence from Spain's Income Tax System

In recent decades, many countries around the world have become more fiscally decentralised. Spain provides a unique case study given it has relatively quickly transitioned from a highly centralised country to a much more decentralised country, although formally not a federation. As part of this decentralisation, autonomy over individual income tax rates and brackets was recently granted to the regions (Autonomous Communities), which are similar to states or provinces in other countries. In the early 2000s, individual income tax brackets and rates were the purview of the central government. Only recently were the Spanish regions granted the authority to levy their own individual income tax rates on a portion of the personal income tax base. Once granted this authority, marginal tax rates diverged substantially at the top of the income distribution, resulting in substantial tax differentials across various regions within Spain. This article reviews the economic consequences of Spanish fiscal decentralisation with a particular focus on the impact on the mobility of high-income individuals and the implications of migration decisions for public finances

Paraísos fiscales, wealth taxation, and mobility

This paper analyzes the effect of wealth taxation on mobility and the consequences for tax revenue and wealth inequality. We exploit the unique decentralization of the Spanish wealth tax system in 2011—after which all regions levied positive tax rates except for Madrid—using linked administrative wealth and income tax records. We find that five years after the reform, the stock of wealthy individuals in the region of Madrid increases by 10% relative to other regions, while smaller tax differentials between other regions do not matter for mobility. We rationalize our findings with a theoretical model of evasion and migration, which suggests that evasion is the mechanism most consistent with all of the mobility response being driven by the paraíso fiscal. Combining new subnational wealth inequality series with our estimated elasticities, we show that Madrid’s status as a tax haven reduces the effectiveness of raising tax revenue and exacerbates regional wealth inequalities

A Cost-based Optimizer for Gradient Descent Optimization

As the use of machine learning (ML) permeates into diverse application domains, there is an urgent need to support a declarative framework for ML. Ideally, a user will specify an ML task in a high-level and easy-to-use language and the framework will invoke the appropriate algorithms and system configurations to execute it. An important observation towards designing such a framework is that many ML tasks can be expressed as mathematical optimization problems, which take a specific form. Furthermore, these optimization problems can be efficiently solved using variations of the gradient descent (GD) algorithm. Thus, to decouple a user specification of an ML task from its execution, a key component is a GD optimizer. We propose a cost-based GD optimizer that selects the best GD plan for a given ML task. To build our optimizer, we introduce a set of abstract operators for expressing GD algorithms and propose a novel approach to estimate the number of iterations a GD algorithm requires to converge. Extensive experiments on real and synthetic datasets show that our optimizer not only chooses the best GD plan but also allows for optimizations that achieve orders of magnitude performance speed-up.Comment: Accepted at SIGMOD 201

Relocation of the rich: migration in response to top tax rate changes from Spanish reforms [WP]

A recent Spanish tax reform granted regions the authority to set income tax rates, resulting in substantial tax differentials. We use individual-level information from Social Security records over a period of one decade. Conditional on moving, taxes have a significant effect on location choice. A one percent increase in the net of tax rate for a region relative to others increases the probability of moving to that region by 1.7 percentage points. Focusing on the stock of top-taxpayers, we estimate an elasticity of the number of top taxpayers with respect to net-of-tax rates of 0.85. Using this elasticity, a theoretical model implies that the mechanical increase in tax revenue due to higher tax rates is larger than the loss in tax revenue from the out-flow of migration

Interaction of Stress, Lead Burden, and Age on Cognition in Older Men: The VA Normative Aging Study

BACKGROUND. Low-level exposure to lead and to chronic stress may independently influence cognition. However, the modifying potential of psychosocial stress on the neurotoxicity of lead and their combined relationship to aging-associated decline have not been fully examined. OBJECTIVES. We examined the cross-sectional interaction between stress and lead exposure on Mini-Mental State Examination (MMSE) scores among 811 participants in the Normative Aging Study, a cohort of older U.S. men. METHODS. We used two self-reported measures of stress appraisal-a self-report of stress related to their most severe problem and the Perceived Stress Scale (PSS). Indices of lead exposure were blood lead and bone (tibia and patella) lead. RESULTS. Participants with higher self-reported stress had lower MMSE scores, which were adjusted for age, education, computer experience, English as a first language, smoking, and alcohol intake. In multivariable-adjusted tests for interaction, those with higher PSS scores had a 0.57-point lower (95% confidence interval, -0.90 to 0.24) MMSE score for a 2-fold increase in blood lead than did those with lower PSS scores. In addition, the combination of high PSS scores and high blood lead categories on one or both was associated with a 0.05-0.08 reduction on the MMSE for each year of age compared with those with low PSS score and blood lead level (p < 0.05). CONCLUSIONS. Psychological stress had an independent inverse association with cognition and also modified the relationship between lead exposure and cognitive performance among older men. Furthermore, high stress and lead together modified the association between age and cognition.National Institutes of Health (R01ES07821, R01HL080674, R01HL080674-02S1, R01ES013744, ES05257-06A1, P20MD000501, P42ES05947, ES03918-02); National Center for Research Resources General Clinical Research Center (M01RR02635); Leaves of Grass Foundation; United States Department of Veterans Affair

Comprehensive Simultaneous Shipboard and Airborne Characterization of Exhaust from a Modern Container Ship at Sea

We report the first joint shipboard and airborne study focused on the chemical composition and water-uptake behavior of particulate ship emissions. The study focuses on emissions from the main propulsion engine of a Post-Panamax class container ship cruising off the central coast of California and burning heavy fuel oil. Shipboard sampling included micro-orifice uniform deposit impactors (MOUDI) with subsequent off-line analysis, whereas airborne measurements involved a number of real-time analyzers to characterize the plume aerosol, aged from a few seconds to over an hour. The mass ratio of particulate organic carbon to sulfate at the base of the ship stack was 0.23 ± 0.03, and increased to 0.30 ± 0.01 in the airborne exhaust plume, with the additional organic mass in the airborne plume being concentrated largely in particles below 100 nm in diameter. The organic to sulfate mass ratio in the exhaust aerosol remained constant during the first hour of plume dilution into the marine boundary layer. The mass spectrum of the organic fraction of the exhaust aerosol strongly resembles that of emissions from other diesel sources and appears to be predominantly hydrocarbon-like organic (HOA) material. Background aerosol which, based on air mass back trajectories, probably consisted of aged ship emissions and marine aerosol, contained a lower organic mass fraction than the fresh plume and had a much more oxidized organic component. A volume-weighted mixing rule is able to accurately predict hygroscopic growth factors in the background aerosol but measured and calculated growth factors do not agree for aerosols in the ship exhaust plume. Calculated CCN concentrations, at supersaturations ranging from 0.1 to 0.33%, agree well with measurements in the ship-exhaust plume. Using size-resolved chemical composition instead of bulk submicrometer composition has little effect on the predicted CCN concentrations because the cutoff diameter for CCN activation is larger than the diameter where the mass fraction of organic aerosol begins to increase significantly. The particle number emission factor estimated from this study is 1.3 × 10^(16) (kg fuel)^(−1), with less than 1/10 of the particles having diameters above 100 nm; 24% of particles (>10 nm in diameter) activate into cloud droplets at 0.3% supersaturation