On the Use of Border Taxes in Developing Countries

Contrary to what is implied by the so called “Wahsington consensus”, Stiglitz (2003) has argued that in the least developed countries border taxes are superior to VAT. However, supported by much respectable research, the IMF and World Bank’s recommend that developing countries substitute VAT for border taxes. The present paper provides an easy to implement parameterised general equilibrium model which may be used as the basis for empirical research, required to reach a consensus opinion within the profession on the issue. The model allows for the fact that different tax systems are associated with different administrative costs, and represents the informal sector as a parameterisation, the CES-UT, of a utility function with explicit representation of the use of time. By means of a quantitative example, it illustrates, on the one hand, that a large informal sector in itself does not justify the use of border taxes, but, on the other hand, when administrative costs of taxation are taken into account, that the size of the informal sector, as claimed as Stiglitz (2003), is indeed important for whether the use of border taxes is desirable or not.Optimal trade policy, VAT, tax-tariff reform, costs of tax administration, informal sector, developing countries

Welfare Effects of Tax and Price Changes Revisited

Dixit’s 1975 paper ‘Welfare Effects of Tax and Price Changes’ cosntitutes a seminal contribution to the theory of tax reform analysis within a second-best general equilibrium framework. The present paper clarifies ambiguities with respect to normalisation which have led to misinterpretation of some Dixit’s analytical results. It proves that a marginal tax reform starting from a proportional tax system will improve social welfare if it increases the supply of labour, whatever the rule of normalisation adopted, and shows that this result provides the key to understanding what determines the optimal system of commodity taxation as reflected in the Corlett and Hague analysis of optimal taxation in an economy with two produced commodities. Recasting work by Deaton (1981b), it generalises, using an alternative definition of the complementarity between consumption and leisure, to an economy with many commodities the insight that the optimal tax system is determined as a trade-off between two objectives : 1) to encourage the supply of labour to the market, and 2) to limit the distorsion of the pattern of consumption of produced commoditie. This insight cannot be illustrated by simulation studies using standard additive separable utility functions. However, extending work of Atkinson and Stern (1080,1981) the paper presents a parameterised utility function with explicit representation of the use of time, the CES-UT, which allows a flexible representation of the relationship between consumption and leisure. This functional form is used to provide a quantitative illustration of the trade-off which defines the optimal tax system and thus desirable directions of tax reform.Public economics, optimal taxation, tax reform, tax simulation, distance functions, CGE models

Constitutive parameter extraction for heated materials

The focus is the determination of the electrical constitutive paramaters of materials with general complex epsilon and mu values at elevated temperatures. Measurement fixtures and techniques are evaluated for frequencies between 8 and 12 GHz using a rectangular waveguide with the sample completely filling the fixture. Three different measurement techniques are evaluated to obtain the necessary measured quantities for parameter extraction. The most desirable technique used two reflection measurements from material samples of different thickness backed with a short. Temperatures up to 600 F were investigated

Magnetic dipole moments in single and coupled split-ring resonators

We examine the role of magnetic dipoles in single and coupled pairs of metallic split-ring resonators by numerically computing their magnitude and examining their relative contributions to the scattering cross section. We demonstrate that magnetic dipoles can strongly influence the scattering cross section along particular directions. It is also found that the magnetic dipole parallel to the incident magnetic field and/or high-order multipoles may play a significant role in the linear response of coupled split-ring resonators.Comment: 7 pages, 3 figures, 1 tabl

Design, theory, and measurement of a polarization insensitive absorber for terahertz imaging

We present the theory, design, and realization of a polarization-insensitive metamaterial absorber for terahertz frequencies. We derive geometrical-independent conditions for effective medium absorbers in general, and for resonant metamaterials specically. Our fabricated design reaches and absorptivity of 78% at 1.145 ThzComment: 6 Pages, 5 figures; figures update

The influence of potassium on core and geodynamo evolution

We model the thermal evolution of the core and mantle using a parametrized convection scheme, and calculate the entropy available to drive the geodynamo as a function of time. The cooling of the core is controlled by the rate at which the mantle can remove heat. Rapid core cooling favours the operation of a geodynamo but creates an inner core that is too large; slower cooling reduces the inner core size but makes a geodynamo less likely to operate. Introducing potassium into the core retards inner core growth and provides an additional source of entropy. For our nominal model parameters, a core containing approximate to 400 ppm potassium satisfies the criteria of present-day inner core size, surface heat flux, mantle temperature and cooling rate, and positive core entropy production.We have identified three possibilities that may allow the criteria to be satisfied without potassium in the core. (1) The core thermal conductivity is less than half the generally accepted value of 50 W m(-1) K-1. (2) The core solidus and adiabat are significantly colder and shallower than results from shock experiments and ab initio simulations indicate. (3) The core heat flux has varied by no more than a factor of 2 over Earth history. All models we examined with the correct present-day inner core radius have an inner core age of < 1.5 Gyr; prior to this time the geodynamo was sustained by cooling and radioactive heat production within a completely liquid core

Arcjet Testing of Micro-Meteoroid Impacted Thermal Protection Materials

There are several harsh space environments that could affect thermal protection systems and in turn pose risks to the atmospheric entry vehicles. These environments include micrometeoroid impact, extreme cold temperatures, and ionizing radiation during deep space cruise, all followed by atmospheric entry heating. To mitigate these risks, different thermal protection material samples were subjected to multiple tests, including hyper velocity impact, cold soak, irradiation, and arcjet testing, at various NASA facilities that simulated these environments. The materials included a variety of honeycomb packed ablative materials as well as carbon-based non-ablative thermal protection systems. The present paper describes the results of the multiple test campaign with a focus on arcjet testing of thermal protection materials. The tests showed promising results for ablative materials. However, the carbon-based non-ablative system presented some concerns regarding the potential risks to an entry vehicle. This study provides valuable information regarding the capability of various thermal protection materials to withstand harsh space environments, which is critical to sample return and planetary entry missions

Critical dynamics of ballistic and Brownian particles in a heterogeneous environment

The dynamic properties of a classical tracer particle in a random, disordered medium are investigated close to the localization transition. For Lorentz models obeying Newtonian and diffusive motion at the microscale, we have performed large-scale computer simulations, demonstrating that universality holds at long times in the immediate vicinity of the transition. The scaling function describing the crossover from anomalous transport to diffusive motion is found to vary extremely slowly and spans at least 5 decades in time. To extract the scaling function, one has to allow for the leading universal corrections to scaling. Our findings suggest that apparent power laws with varying exponents generically occur and dominate experimentally accessible time windows as soon as the heterogeneities cover a decade in length scale. We extract the divergent length scales, quantify the spatial heterogeneities in terms of the non-Gaussian parameter, and corroborate our results by a thorough finite-size analysis.Comment: 14 page

Molecular and biochemical characterization of a new thermostable bacterial laccase from<i> Meiothermus ruber</i> DSM 1279

A new bacterial laccase gene (mrlac) fromMeiothermus ruberDSM 1279 was successfully overexpressed to produce a laccase (Mrlac) in soluble form inEscherichia coliduring simultaneous overexpression of a chaperone protein (GroEL/ES).</p

Trigger-Point Self-Care for Chronic Neck Pain: Pilot and Feasibility

poster abstractMassage is a non-pharmacological approach for neck pain with building evidence. Trigger points (TrPts) are thought to be associated with chronic neck pain (CNP) and can be treated with massage techniques. Due to massage’s out-of-pocket costs, TrPt self-care (TrPtSC) may serve as a cost-effective treatment that may reach broader populations. No study has examined a) feasibility of conducting TrPtSC training in a research setting, b) ability of such programs to meet stated training objectives, c) adherence to personalized TrPtSC plans, and d) TrPtSC outcomes for CNP. A pilot observational, pre- post-intervention cohort study with 1-, 4-, and 8-week follow-ups was implemented. Participants: self-identified adults with CNP and Neck Disability Index (NDI) ≥4. Measures: pre-/post-TrPtSC training objectives survey, TrPtSC daily self-report log, NDI and 11-point pain rating scale. Intervention: three-hour TrPtSC training with interactive lecture, demonstration, supervised practice, and private assessment with individualized TrPtSC plan development. Handouts and tools were provided for training and home TrPtSC. Participants documented their individualized TrPtSC plan adherence daily. Five participants (women=3; ages 22-58; White=5) enrolled in the study and two separate group training sessions occurred (n=3 & 2, respectively). By the end of the TrPtSC training, all participants agreed or strongly agreed they achieved all intended training objectives. Baseline NDI categorized all participants as mild neck pain with disability (mean NDI=10.4±2.1). Week-1 follow-up: 1 participant had no NDI change, 1 participant worsened, and 3 reported 23-50% improvement. All participants had improved NDI at week-4 and week-8 compared to baseline. Three participants reported 23-30% improvement by study’s end. Our TrPtSC group training approach met objectives and our study design is feasible for larger scale trials. Results suggest TrPtSC may improve CNP outcomes. More robust studies with greater than mild neck pain and disability participants are needed to estimate effect sizes and adequately power larger comparison trials