Issues in the Taxation of Foreign Source Income

This paper examines some aspects of the tax treatment of U.S. multinational corporations. The emphasis is on problems of coordination of the different tax systems faced by the firms. The U.S. corporate income tax must take account of the fact that the firms' over- seas income is taxed by the host governments, in a variety of ways. Currently, the foreign tax credit is the principle mechanism for making these adjustments; it is examined, along with alternative methods such as territorial treatment and a deduction for foreign taxes. The paper also considers the closely related question of coordinating measures of taxable income. The most common method, the arm's length rule, is examined. Alternatives to it, including allocation by shares and a partial case involving allocation of research and development expenses, are also considered. First, the revenue effects of these tax regimes are simulated, with no behavioral responses considered. Responses in location of investment decisions are then included. The data are taken from the corporations' U.S. tax returns, cross-tabulated into approximately 240 industry and country cells.

Clinical and Procedural Effects of Transitioning to Contact Force Guided Ablation for Atrial Fibrillation.

Background: A major innovation in atrial fibrillation (AF) ablation has been the introduction of contact force (CF) sensing catheters. Objective: To evaluate procedural and clinical effects of transitioning to CF-guided AF ablation. Methods: Consecutive AF ablation patients were studiedduring the period of time of transitioning from a non-CF to CF sensing catheter. Procedural data recorded was total radiofrequency time, time to isolate the left pulmonary veins (LPVs), and time to isolate the right pulmonary veins (RPVs). Clinically, the 3 and 12-month maintenance of sinus rhythm was noted and compared by: paroxysmal vs. persistent AF; CT scan LA volume more or less than 150 cc; CHA2DS2VASC more or less than 2; and LVEF more or less than 55%. Safety data was recorded as well. Results: Total ablation times were shorter (113 vs.146 min, p=0.011)when using the CF catheters compared to non-CF ablations. This was driven by a decrease in both LPV (46 vs.72 min, p\u3c0.001) and RPV time (54 vs. 75 min, p=0.002).The use of CF catheter did not change the overall percentage of patients in sinus rhythm at 3 and 12-months of follow up. However, sinus rhythm was more frequent at 12 months with CF ablation inpatients with an LA volume of more than 150 cc when compared to non-CF ablation (84.6% and 52.4%, p=0.03). There was no difference in outcomes with stratification by CHA2DS2VASC score or LVEF. No significant difference in complications was noted. Conclusions: For AF ablation, the initial use of CF-sensing technology reduced procedure times with similar overall sinus rhythm maintenance at 3 and 12 months. CF improved 12-month outcomes in patients with an enlarged LA

Local Government Budgeting: The Econometric Comparison of Political and Bureaucratic Models

The current paper presents a method of deciding the question of whether any given stage in the budget process is an example of the "political" or the "bureaucratic" model. We then use it to study local government spending on education. The basis for our method is the important difference between the effect of intergovernmental aid that is implied by the political budget model and by the bureaucratic budget model. According to the bureaucratic model, the effect of inter-governmental aid on each category of educational input (e.g., teachers' salaries, books, etc.) depends only on the change in total educational spending induced by the aid and not on the type of aid that causes the change in spending. In contrast, the political budget model implies that the overall expenditure increase is the result of separate decisions on each of the expenditure categories and that the changes in these expenditure categories will depend on the form of the intergovernmental aid. Our method of exploiting this difference is presented in detail below.

Taxation and the Location of U.S. Investment Abroad

Tax policy toward the overseas income of U.S. firms is an important issue since foreign investment accounts for a sizabLe fraction of total investment by U.S. firms. At present there is no consensus on the degree to which U.S. firms respond to tax incentives when making international investment decisions. This paper seeks to shed light on this issue. Because the tax systems of (at least) two countries are involved,the specification of tax incentives is far from trivial. For example, U.S.treatment is based on the foreign tax credit mechanism. In its purest form,this mechanism would insure that the net tax rate on all income of U.S. firms would be equal to the U.S. rate, rendering the tax rates in the host countries irrelevant. In fact, actual U.S. tax practice is far removed from an idealized foreign tax credit mechanism. For instance the U.S. tax is not collected until income is repatriated from abroad; section I points out that deferral changes the incentive effects in fundamental ways. Foreign income tax rates definitely do matter in theory; in fact, they may be of overriding importance.The remainder of the paper seeks to test these theoretical considerations. First,we describe the cross-section data that were collected for this purpose. Then, we report the result that U.S. firms respond to net rates of return in general and to properly specified tax rates in particular.

A systematic correlation between two-dimensional flow topology and the abstract statistics of turbulence

Velocity differences in the direct enstrophy cascade of two-dimensional turbulence are correlated with the underlying flow topology. The statistics of the transverse and longitudinal velocity differences are found to be governed by different structures. The wings of the transverse distribution are dominated by strong vortex centers, whereas, the tails of the longitudinal differences are dominated by saddles. Viewed in the framework of earlier theoretical work this result suggests that the transfer of enstrophy to smaller scales is accomplished in regions of the flow dominated by saddles.Comment: 4 pages, 4 figure

The Velocity Distribution of the Nearest Interstellar Gas

The bulk flow velocity for the cluster of interstellar cloudlets within about 30 pc of the Sun is determined from optical and ultraviolet absorption line data, after omitting from the sample stars with circumstellar disks or variable emission lines and the active variable HR 1099. Ninety-six velocity components towards the remaining 60 stars yield a streaming velocity through the local standard of rest of -17.0+/-4.6 km/s, with an upstream direction of l=2.3 deg, b=-5.2 deg (using Hipparcos values for the solar apex motion). The velocity dispersion of the interstellar matter (ISM) within 30 pc is consistent with that of nearby diffuse clouds, but present statistics are inadequate to distinguish between a Gaussian or exponential distribution about the bulk flow velocity. The upstream direction of the bulk flow vector suggests an origin associated with the Loop I supernova remnant. Groupings of component velocities by region are seen, indicating regional departures from the bulk flow velocity or possibly separate clouds. The absorption components from the cloudlet feeding ISM into the solar system form one of the regional features. The nominal gradient between the velocities of upstream and downstream gas may be an artifact of the Sun's location near the edge of the local cloud complex. The Sun may emerge from the surrounding gas-patch within several thousand years.Comment: Typographical errors corrected; Five tables, seven figures; Astrophysical Journal, in pres

Simulating Three-Dimensional Hydrodynamics on a Cellular-Automata Machine

We demonstrate how three-dimensional fluid flow simulations can be carried out on the Cellular Automata Machine 8 (CAM-8), a special-purpose computer for cellular-automata computations. The principal algorithmic innovation is the use of a lattice-gas model with a 16-bit collision operator that is specially adapted to the machine architecture. It is shown how the collision rules can be optimized to obtain a low viscosity of the fluid. Predictions of the viscosity based on a Boltzmann approximation agree well with measurements of the viscosity made on CAM-8. Several test simulations of flows in simple geometries -- channels, pipes, and a cubic array of spheres -- are carried out. Measurements of average flux in these geometries compare well with theoretical predictions.Comment: 19 pages, REVTeX and epsf macros require

Anomalous roughness with system size dependent local roughness exponent

We note that in a system far from equilibrium the interface roughening may depend on the system size which plays the role of control parameter. To detect the size effect on the interface roughness, we study the scaling properties of rough interfaces formed in paper combustion experiments. Using paper sheets of different width \lambda L, we found that the turbulent flame fronts display anomalous multi-scaling characterized by non universal global roughness exponent \alpha and the system size dependent spectrum of local roughness exponents,\xi_q, whereas the burning fronts possess conventional multi-affine scaling. The structure factor of turbulent flame fronts also exhibit unconventional scaling dependence on \lambda These results are expected to apply to a broad range of far from equilibrium systems, when the kinetic energy fluctuations exceed a certain critical value.Comment: 33 pages, 16 figure