Tax Competition for Heterogeneous Firms with Endogenous Entry

This paper models tax competition for mobile firms that are differentiated by the amount of labor needed to cover fixed costs. Because tax competition affects the distribution of firms, it affects both relative equilibrium wages across countries and equilibrium prices. These in turn influence the equilibrium number of firms. From the social planner's perspective, optimal tax rates are harmonized, providing the optimal number of firms, and set such that income is efficiently distributed between private and public consumption. As is common in tax competition models, in the Nash equilibrium tax rates are inefficiently low, yielding underprovision of public goods. Furthermore, there exist a variety of situations in which equilibrium tax rates differ. As a result, too many firms enter the market as governments compete to be the low-tax, high-wage country. This illustrates a new distortion from tax competition and provides an additional benefit from tax harmonization.Tax Competition, Foreign Direct Investment, Tax Harmonization

Tax Competition for Heterogeneous Firms with Endogenous Entry:The Case of Heterogeneous Fixed Costs

This paper models tax competition for mobile firms that are differentiated by the amount of labor needed to cover fixed costs. Because tax competition affects the distribution of firms, it affects both relative equilibrium wages across countries and equilibrium prices. These in turn influence the equilibrium number of firms. From the social planner's perspective, optimal tax rates are harmonized, providing the optimal number of firms, and set such that income is efficiently distributed between private and public consumption. As is common in tax competition models, in the Nash equilibrium tax rates are inefficiently low, yielding underprovision of public goods. Furthermore, there exist a variety of situations in which equilibrium tax rates differ. As a result, too many firms enter the market as governments compete to be the low-tax, high-wage country. This illustrates a new distortion from tax competition and provides an additional benefit from tax harmonization.Tax Competition, Foreign Direct Investment, Tax Harmonization

Tax Competition for Heterogeneous Firms with Endogenous Entry: The Case of Heterogeneous Fixed Costs

This paper models tax competition for mobile firms that are differentiated by the amount of labor needed to cover fixed costs. Because tax competition affects the distribution of firms, it affects both relative equilibrium wages across countries and equilibrium prices. These in turn influence the equilibrium number of firms. From the social planner's perspective, optimal tax rates are harmonized, providing the optimal number of firms, and set such that income is efficiently distributed between private and public consumption. As is common in tax competition models, in the Nash equilibrium tax rates are inefficiently low, yielding underprovision of public goods. Furthermore, there exist a variety of situations in which equilibrium tax rates differ. As a result, too many firms enter the market as governments compete to be the low-tax, high-wage country. This illustrates a new distortion from tax competition and provides an additional benefit from tax harmonization.Tax Competition, Foreign Direct Investment, Tax Harmonization

Tax Competition for Heterogeneous Firms with Endogenous Entry

This paper models tax competition for mobile firms that are differentiated by the amount of labor needed to cover fixed costs. Because tax competition affects the distribution of firms, it affects both relative equilibrium wages across countries and equilibrium prices. These in turn influence the equilibrium number of firms. From the social planner's perspective, optimal tax rates are harmonized, providing the optimal number of firms, and set such that income is efficiently distributed between private and public consumption. As is common in tax competition models, in the Nash equilibrium tax rates are inefficiently low, yielding underprovision of public goods. Furthermore, there exist a variety of situations in which equilibrium tax rates differ. As a result, too many firms enter the market as governments compete to be the low-tax, high-wage country. This illustrates a new distortion from tax competition and provides an additional benefit from tax harmonization.Tax Competition, Foreign Direct Investment, Tax Harmonization

A rapidly expanding Bose-Einstein condensate: an expanding universe in the lab

We study the dynamics of a supersonically expanding ring-shaped Bose-Einstein condensate both experimentally and theoretically. The expansion redshifts long-wavelength excitations, as in an expanding universe. After expansion, energy in the radial mode leads to the production of bulk topological excitations -- solitons and vortices -- driving the production of a large number of azimuthal phonons and, at late times, causing stochastic persistent currents. These complex nonlinear dynamics, fueled by the energy stored coherently in one mode, are reminiscent of a type of "preheating" that may have taken place at the end of inflation.Comment: 12 pages, 7 figure

Exact results for nonlinear ac-transport through a resonant level model

We obtain exact results for the transport through a resonant level model (noninteracting Anderson impurity model) for rectangular voltage bias as a function of time. We study both the transient behavior after switching on the tunneling at time t = 0 and the ensuing steady state behavior. Explicit expressions are obtained for the ac-current in the linear response regime and beyond for large voltage bias. Among other effects, we observe current ringing and PAT (photon assisted tunneling) oscillations.Comment: 7 page

Vibration-enhanced quantum transport

In this paper, we study the role of collective vibrational motion in the phenomenon of electronic energy transfer (EET) along a chain of coupled electronic dipoles with varying excitation frequencies. Previous experimental work on EET in conjugated polymer samples has suggested that the common structural framework of the macromolecule introduces correlations in the energy gap fluctuations which cause coherent EET. Inspired by these results, we present a simple model in which a driven nanomechanical resonator mode modulates the excitation energy of coupled quantum dots and find that this can indeed lead to an enhancement in the transport of excitations across the quantum network. Disorder of the on-site energies is a key requirement for this to occur. We also show that in this solid state system phase information is partially retained in the transfer process, as experimentally demonstrated in conjugated polymer samples. Consequently, this mechanism of vibration enhanced quantum transport might find applications in quantum information transfer of qubit states or entanglement.Comment: 7 pages, 6 figures, new material, included references, final published versio