929 research outputs found

    Information and Multi-Period Optimal Income Taxation with Government Commitment

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    The optimal income taxation problem has been extensively studied in one- period models. When consumers work for many periods, this paper analyzes what information, if any, that the government learns about abilities in one period can be used in later periods to attain more redistribution than in a one- period world. liken the government must commit itself to future tax schedules, the gains cane from relaxing self-selection constraints by intertemporal nonstationarity. The effect of nonstationarity is analogous to that of randomization in one-period models. In a model with two ability classes it is shown that the key use of information is that only a single lifetime self-selection constraint for each type of consumer must be imposed. Sane necessary and sufficient conditions for randomization or nonstationarity are given. The planner can make additional use of the information when individual and social rates of time discounting differ. In this case, the limiting tax schedule is a nondistorting one if the government has a lower discount rate than individuals.

    Dynamic Optimal Income Taxation with Government Commitment

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    The optimal income taxation problem has been extensively studied in one-period models. This paper analyzes optimal income taxation when consumers work for many periods. We also analyze what information, if any, that the government learns about abilities in one period can be used in later periods to attain more redistribution than in a one-period world. When the government must commit itself to future tax schedules, intertemporal nonstationarity of tax schedules could relax the self-selection constraints and lead to Pareto improvements. The effect of nonstationarity is analogous to that of randomization in one-period models. The use of information is limited since only a single lifetime self-selection constraint for each type of consumer exists. These results hold when individuals and the government have the same discount rates. The planner can make additional use of the information when individual and social rates of time discounting differ. In this case, the limiting tax schedule is a nondistorting one if the government has a lower discount rate than individuals.

    Noncommutative field gas driven inflation

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    We investigate early time inflationary scenarios in an Universe filled with a dilute noncommutative bosonic gas at high temperature. A noncommutative bosonic gas is a gas composed of bosonic scalar field with noncommutative field space on a commutative spacetime. Such noncommutative field theories was recently introduced as a generalization of quantum mechanics on a noncommutative spacetime. As key features of these theories are Lorentz invariance violation and CPT violation. In the present study we use a noncommutative bosonic field theory that besides the noncommutative parameter θ\theta shows up a further parameter σ\sigma. This parameter σ\sigma controls the range of the noncommutativity and acts as a regulator for the theory. Both parameters play a key role in the modified dispersion relations of the noncommutative bosonic field, leading to possible striking consequences for phenomenology. In this work we obtain an equation of state p=ω(σ,θ;β)ρp=\omega(\sigma,\theta;\beta)\rho for the noncommutative bosonic gas relating pressure pp and energy density ρ\rho, in the limit of high temperature. We analyse possible behaviours for this gas parameters σ\sigma, θ\theta and β\beta, so that 1ω<1/3-1\leq\omega<-1/3, which is the region where the Universe enters an accelerated phase.Comment: Reference added. Version to appear in Journal of Cosmology and Astroparticle Physics - JCA

    Pareto Efficient Tax Structures

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    Most analyses of optimal income taxation make restrictive technical assumptions on preferences (such as single-crossing) and only derive properties of welfare-maximizing tax schedules. Here, for an economy with any finite numbers of groups and commodities, Pareto efficient tax structures are described assuming only continuity and monotonicity of preferences. Most results follow directly from a property of self-selection: at an optimum, one group will never envy the bundle of another group which pays a larger total tax. The bundle of a group paying the largest total tax is undistorted. Assuming normality, undistorted outcomes for a group form a connected segment on the constrained utility possibility frontier. The tax structure at distorted outcomes is also described.

    Randomization in Optimal Income Tax Schedules

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    The optimal income tax problem, since it requires self-selection constraints which define nonconvex feasible sets, is one of the many problems in economics for which randomization in the solution may be desirable. For a two-class economy. we characterize the optimal random tax schedules and we present necessary and sufficient conditions for the desirability of local randomization. The standard single-crossing restriction on preferences is not required for these results. We also show that randomization can be beneficial without violating (ex post as well as ex ante) horizontal equity. Lastly, we give an example to demonstrate that the gains from randomization may be large.

    Targeted Imaging of Urothelium Carcinoma in Human Bladders by an ICG pHLIP Peptide Ex vivo

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    Bladder cancer is the fifth most common in incidence and one of the most expensive cancers to treat. Early detection greatly improves the chances of survival and bladder preservation. The pH Low Insertion Peptide (pHLIP® peptide) conjugated with a near infrared fluorescent dye (ICG) targets low extracellular pH allowing visualization of malignant lesions in human bladder carcinoma ex vivo. Cystectomy specimens obtained after radical surgery were immediately irrigated with non-buffered saline and instilled with a solution of the ICG pHLIP® construct, incubated, and rinsed. Bladders were subsequently opened and imaged, the fluorescent spots were marked, and a standard pathological analysis was carried out to establish the correlation between ICG pHLIP® imaging and white light pathological assessment. Accurate targeting of bladder lesions was achieved with a sensitivity of 97%. Specificity is 100%, but reduced to 80%, if targeting of necrotic tissue from previous transurethral resections or chemotherapy are considered as false positives. ICG pHLIP® imaging agent marked high grade urothelial carcinomas, both muscle invasive and non-muscle invasive. Carcinoma in situ (CIS) was accurately diagnosed in 11 cases, whereas only 4 cases were seen using white light, so imaging with the ICG pHLIP® peptide offers improved early diagnosis of bladder cancers, and may also enable new treatment alternatives

    Catalytic Conversion of Glycerol to Bio-Based Aromatics

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    Green application of biodiesel-derived glycerol will boost biodiesel production in terms of sustainability and economics. The glycerol to liquid fuels is a promising route that provides an additional energy source, which contributes significantly to energy transition besides biodiesel. This pathway could generate alkyl-aromatic hydrocarbons with a yield of ∼60%, oxygenates, and gases. MFI Zeolites (H-ZSM-5) catalysts are mainly used to propagate the aromatization pathway. This chapter presents the pathways, challenges, catalytic design, influences of catalyst acidity, metal addition, reaction condition, and catalysts deactivation on glycerol conversion to hydrocarbon fuels and aromatics. Studies revealed that time on stream, temperature, and weight hourly space velocity (range of 0.1–1 h−1) influences the benzene, toluene, and xylene BTX and benzene, toluene, ethylbenzene, and xylene BTEX yield. Acidity of the H-ZSM-5 could be tailored by metals, additives, and binders. Bronsted acidity promotes coke formation which results in reversible deactivation of the H-ZSM-5 catalyst. It is hoped that this study will promote intensified research on the use of glycerol for purposes of fuel generating and valuable products
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