Corruption and bureaucratic structure in a developing economy

We address the impact of corruption in a developing economy in the context of an empirically relevant hold-up problem - when a foreign firm sinks an investment to provide infrastructure services. We focus on the structure of the economy’s bureaucracy, which can be centralized or decentralized, and characterize the ‘corruptibility’ of bureaucrats in each case. Results are explained in terms of the noninternalization, under decentralization, of the ‘bribe externality’ and the ‘price externality.’ In welfare terms, decentralization is favoured, relatively speaking, if the tax system is less inefficient, funding is less tight, bureaucrats are less venal, or compensation for expropriation is ungenerous

Regulatory barriers and entry in developing economies

We model entry by entrepreneurs into new markets in developing economies with regulatory barriers in the form of licence fees and bureaucratic delay. Because laissez faire leads to ‘excessive’ entry, a licence fee can increase welfare by discouraging entry. However, in the presence of a licence fee, bureaucratic delay creates a strategic opportunity, which can result in both greater entry by first movers and a higher steady-state number of firms. Delay also leads to speculation, with entrepreneurs taking out licences to obtain the option of immediate entry if they later observe the industry to be profitable enough

On entanglement-assisted classical capacity

This paper is essentially a lecture from the author's course on quantum information theory, which is devoted to the result of C. H. Bennett, P. W. Shor, J. A. Smolin and A. V. Thapliyal (quant-ph/0106052) concerning entanglement-assisted classical capacity of a quantum channel. A modified proof of this result is given and relation between entanglement-assisted and unassisted classical capacities is discussed.Comment: 10 pages, LATE

Entanglement of pure states for a single copy

An optimal local conversion strategy between any two pure states of a bipartite system is presented. It is optimal in that the probability of success is the largest achievable if the parties which share the system, and which can communicate classically, are only allowed to act locally on it. The study of optimal local conversions sheds some light on the entanglement of a single copy of a pure state. We propose a quantification of such an entanglement by means of a finite minimal set of new measures from which the optimal probability of conversion follows.Comment: Revtex, 4 pages, no figures. Minor changes. Appendix remove

Handbook of noise ratings

Handbook announced in Tech Brief is compendium of information describing multifarious noise methods now in use. Reference material gives user better access to definitions, application, and calculation procedures of current noise rating methods

Full counting statistics and conditional evolution in a nanoelectromechanical system

We study theoretically the full distribution of transferred charge in a tunnel junction (or quantum point contact) coupled to a nanomechanical oscillator, as well as the conditional evolution of the oscillator. Even if the oscillator is very weakly coupled to the tunnel junction, it can strongly affect the tunneling statistics and lead to a highly non-Gaussian distribution. Conversely, given a particular measurement history of the current, the oscillator energy distribution may be localized and highly non-thermal. We also discuss non-Gaussian correlations between the oscillator motion and tunneling electrons; these show that the tunneling back-action cannot be fully described as an effective thermal bath coupled to the oscillator.Comment: 7 pages; figure added; typos correcte

Mixedness and teleportation

We show that on exceeding a certain degree of mixedness (as quantified by the von Neumann entropy), entangled states become useless for teleporatation. By increasing the dimension of the entangled systems, this entropy threshold can be made arbitrarily close to maximal. This entropy is found to exceed the entropy threshold sufficient to ensure the failure of dense coding.Comment: 6 pages, no figure

Quantifying nonorthogonality

An exploratory approach to the possibility of analyzing nonorthogonality as a quantifiable property is presented. Three different measures for the nonorthogonality of pure states are introduced, and one of these measures is extended to single-particle density matrices using methods that are similar to recently introduced techniques for quantifying entanglement. Several interesting special cases are considered. It is pointed out that a measure of nonorthogonality can meaningfully be associated with a single mixed quantum state. It is then shown how nonorthogonality can be unlocked with classical information; this analysis reveals interesting inequalities and points to a number of connections between nonorthogonality and entanglement.Comment: Accepted for publication in Phys. Rev.