142 research outputs found
Fair Collective Choice Rules: Their Origin and Relationship
This paper provides a conceptual framework on fair collective choice rules that synthesizes the studies of Goldman and Sussangkarn (1978) and Suzumura (1981) on the one hand and Tadenuma (2002, 2005) on the other. We show that both frameworks have the following binary relation as a common origin: an allocation x is at least as good as an allocation z if (i) x Pareto dominates z, or (ii) x equity-dominates z. Its transitive-closure and the strict relation derive different ranking criteria, but remarkably, with respect to the maximal elements, they have a set-inclusive relationship.Welfare Economics, Social Choice, Efficiency, Equity, No-Envy
Optimal Commodity Taxation for Reduction of Envy
This paper derives optimal commodity taxes in a two-class economy, based on Chaudhuri (1986) and Diamantaras and Thomson's (1990) λ-equitability. An allocation is λ-equitable if no agent envies a proportion λ of the bundle of any other agent. We examine the properties of Pareto undominated allocations for various λ-equitability requirements. In contrast with the classic Ramsey rule and its extension, ceteris paribus, the goods preferred by the low skilled agent and/or of high Hicksian elasticities are taxed more heavily. As to the total tax burden, the envying agent may bear a higher tax burden, since the good which he likes should be taxed more heavily to reduce envy. Also, due to the conflict between welfare of the envying agent and his envy, there exists an economy in which the Diamantaras-Thomson allocation -- an allocation which maximizes λ in the range of Pareto efficient allocations -- is the Pareto efficient allocation which minimizes the welfare of the envying agent.Optimal Taxation, Envy
Optimal Nonlinear Income Taxation for Reduction of Envy
This paper examines the optimal nonlinear income taxation problem based on Chaudhuri (1986) and Diamantaras and Thomson's (1990) λ-equitability in a two-class economy. An allocation is λ-equitable if no agent envies a proportion λ of the bundle of any other agent. We examine the properties of Pareto undominated allocations for various λ-equitability requirements. When there is one output, the marginal income tax rate can increase only if (but not if) leisure is a luxury. In a multi-commodity model with commodity taxes, the goods preferred by the low skilled agent and/or of high Hicksian elasticities are taxed more heavily.Income Taxation, Envy
Tax Implementability of Fair Allocations
This paper examines the tax implementability of allocations based on Foley's (1967) concept of fairness as no-envy (or envy-free) and its alternatives. An allocation is tax implementable if there exists a tax schedule under which the allocation is realized as a result of agents' optimization. Tillmann (1984) and Bös and Tillmann (1985) showed that the class of fair allocations that are income tax implementable is quite limited. This paper examines the implementability of fair allocations by a tax schedule that depends on labor supply and gross income ((y,l)-implementability), whose availability is supported by Dasgupta and Hammond (1980), Tillmann (1989), Kolm (1997), Beaudry and Blackorby (1997) and others. A relevant incentive constraint is perishability of abilities, where agents can exert a lower ability level than they actually possess. We first show that in any economy, every envy-free allocation is (y,l)-implementable. On the other hand, we can show that perishability of abilities results in the impossibility of (y,l)-implementability of the egalitarian equivalence (Pazner and Schmeidler (1978a)), the l*-equal budget allocation (Kolm (1996, 1997), Maniquet (1998)), and the balanced-envy allocation (Daniel (1975)). Among them, a special form of the egalitarian equivalence examined by Fleurbaey and Maniquet (1999) and others is (y,l)-implementable in a class of preference-skill distributions where the lazier agent has the higher skill.Tax Implementability, Envy-free
Taxing Mobile and Overconfident Top Earners
We set up a simple model of tax competition for mobile, highly-skilled and overconfident managers. Firms endogenously choose the compensation scheme for managers, which consists of a fixed wage and a bonus payment in the high state. Managers are overconfident about the probability of the high state and hence of receiving the bonus, whereas firms and governments are not. When governments maximize tax revenues, we show that overconfidence unambiguously reduces the bonus tax rate that governments set in the non-cooperative tax equilibrium, while increasing tax revenues. When the government objective incorporates the welfare of resident managers, however, bonus taxes also serve a corrective role and may rise in equilibrium when overconfidence is increased
Education Choices, Longevity and Optimal Policy in a Ben-Porath Economy
We develop a 3-period overlapping generations (OLG) model where individuals borrow at the young age to finance their education. Education does not only increase future wages, but, also, raises the duration of life, which, in turn, affects education choices, in line with Ben Porath (1967). We first identify conditions that guarantee the existence of a stationary equilibrium with perfect foresight. Then, we reexamine the conditions under which the Ben-Porath effect prevails, and emphasize the impact of human capital decay and preferences. We compare the laissez-faire with the social optimum, and show that the latter can be decentralized provided the laissez-faire capital stock corresponds to the one satisfying the modified Golden Rule. Finally, we introduce intracohort heterogeneity in the learning ability, and we show that, under asymmetric information, the second-best optimal non-linear tax scheme involves a downward distortion in the level of education of less able types, which, quite paradoxically, would reinforce the longevity gap in comparison with the laissez-faire
Old age or dependence. Which social insurance?
We consider a society where individuals differ according to their pro- ductivity and their risks of mortality and dependency. We show that according to the most reasonable estimates of correlations among these three characteristics, if one had to choose between a public pension sys- tem and a long-term care social insurance, the latter should be chosen by a utilitarian social planner. For a Rawlsian planner, the balance between the two schemes does depend on a comparison of the ratio of the survival probability to the dependence risk of the poor with its population average
Bordetella pertussis population dynamics and phylogeny in Japan after adoption of acellular pertussis vaccines
Bordetella pertussis, the causative agent of whooping cough, has experienced a resurgence in the past 15 years, despite the existence of both whole-cell and acellular vaccines. Here, we performed whole genome sequencing analysis of 149 clinical strains, provided by the National Institute of Infectious Diseases (NIID), Japan, isolated in 1982-2014, after Japan became the first country to adopt acellular vaccines against B. pertussis. Additionally, we sequenced 39 strains provided by the Konan Kosei Hospital in Aichi prefecture, Japan, isolated in 2008-2013. The genome sequences afforded insight into B. pertussis genome variability and population dynamics in Japan, and revealed that the B. pertussis population in Japan was characterized by two major clades that divided more than 40 years ago. The pertactin gene was disrupted in about 20 % of the 149 NIID isolates, by either a deletion within the signal sequence (ΔSS) or the insertion of IS element IS481 (prn :: IS481). Phylogeny suggests that the parent clones for these isolates originated in Japan. Divergence dating traced the first generation of the pertactin-deficient mutants in Japan to around 1990, and indicated that strains containing the alternative pertactin allele prn2 may have appeared in Japan around 1974. Molecular clock data suggested that observed fluctuations in B. pertussis population size may have coincided with changes in vaccine usage in the country. The continuing failure to eradicate the disease warrants an exploration of novel vaccine compositions
Spatiotemporal T790M Heterogeneity in Individual Patients with EGFR-Mutant Non–Small-Cell Lung Cancer after Acquired Resistance to EGFR-TKI
IntroductionEpidermal growth factor receptor (EGFR) mutation T790M accounts for approximately half of acquired resistances to EGFR-tyrosine kinase inhibitor (TKI). Because T790M is mediated by TKI exposure, its penetration and “on–off” may affect T790M status.MethodsWe retrospectively reviewed T790M status and clinical course of patients who had undergone multiple rebiopsies after acquired resistance to EGFR-TKI.ResultsOf 145 patients with EGFR-mutant NSCLC receiving rebiopsy after acquired resistance, 30 underwent multiple site rebiopsies, and 24 received repeated rebiopsies at the same lesion. In 22 patients who underwent rebiopsies from both central nervous system (CNS; 20 cerebrospinal fluids [CSF] and 2 brain tumoral tissues) and thoracic lesions (7 lung tissues, 14 pleural effusions, and 1 lymph node), 12 were thoracic-T790M-positive. Of these 12 patients, 10 were CNS-T790M-negative, despite exhibiting thoracic-T790M-positive. All 10 thoracic-T790M-negatives were CNS-T790M-negative. Three patients revealed a spatial heterogeneous T790M status among their thoracic lesions. In 24 patients receiving repeated rebiopsies at the same lesion (12 lung tissues, 6 CSFs, and 6 pleural effusions), T790M status of lung lesions varied in five patients after TKI-free interval. In all five patients whose T790M status changed from positive to negative, EGFR-TKI rechallenge was effective. In three of these five patients, after further TKI exposure, T790M status changed from negative to positive again. There was also a patient whose CSF T790M status changed from negative to positive after high-dose erlotinib therapy.ConclusionsT790M status in an individual patient can be spatiotemporally heterogeneous because of selective pressure from EGFR-TKI
Sequence of the Gonium pectorale mating locus reveals a complex and dynamic history of changes in volvocine algal mating haplotypes
Citation: Hamaji, T., Mogi, Y., Ferris, P. J., Mori, T., Miyagishima, S., Kabeya, Y., . . . Nozaki, H. (2016). Sequence of the Gonium pectorale mating locus reveals a complex and dynamic history of changes in volvocine algal mating haplotypes. G3: Genes, Genomes, Genetics, 6(5), 1179-1189. doi:10.1534/g3.115.026229Additional Authors: Nozaki, H.Sex-determining regions (SDRs) or mating-type (MT) loci in two sequenced volvocine algal species, Chlamydomonas reinhardtii and Volvox carteri, exhibit major differences in size, structure, gene content, and gametolog differentiation. Understanding the origin of these differences requires investigation of MT loci from related species. Here, we determined the sequences of the minus and plus MT haplotypes of the isogamous 16-celled volvocine alga, Gonium pectorale, which is more closely related to the multicellular V. carteri than to C. reinhardtii. Compared to C. reinhardtiiMT, G. pectoraleMT is moderately larger in size, and has a less complex structure, with only two major syntenic blocs of collinear gametologs. However, the gametolog content of G. pectoraleMT has more overlap with that of V. carteriMT than with C. reinhardtiiMT, while the allelic divergence between gametologs in G. pectorale is even lower than that in C. reinhardtii. Three key sex-related genes are conserved in G. pectorale MT: GpMID and GpMTD1 in MT-, and GpFUS1 in MT+. GpFUS1 protein exhibited specific localization at the plus-gametic mating structure, indicating a conserved function in fertilization. Our results suggest that the G. pectorale-V. carteri common ancestral MT experienced at least one major reformation after the split from C. reinhardtii, and that the V. carteri ancestral MT underwent a subsequent expansion and loss of recombination after the divergence from G. pectorale. These data begin to polarize important changes that occurred in volvocine MT loci, and highlight the potential for discontinuous and dynamic evolution in SDRs. © 2016 Hamaji et al
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