Are Palmore's "ignored estimates" on the number of planar central configurations correct?

We wish to draw attention on estimates on the number of relative equilibria in the Newtonian $n$-body problem that Julian Palmore published in 1975.Comment: 4 page

Evaluating the Efficiency and Equity of Federal Fiscal Equalization

In theory, federal transfers that make household location decisions efficient should ignore local cost differences, subsidize positive externalities, and offset differences in federal-tax payments and local taxes levied on non-residents, but not local tax revenues from residents. Transfers that redistribute resources equitably across regions will likely target areas with individuals of low earnings potential or low real incomes. Applying these criteria empirically, Canadian equalization policy appears neither efficient nor equitable, but exacerbates pre-existing inefficiencies and underfunds minorities. Locational inefficiencies cost Canada 0.41 percent of income annually and cause over-funded provinces to have populations 31 percent beyond their efficient long-run levels. The hard copy version of this paper was accidentally printed without tables. Print subscribers may access the full file by downloading here. Individual purchasers of paper copies can email [email protected] for the full file. Our apologies for the error.

Are Houses Too Big or In the Wrong Place? Tax Benefits to Housing and Inefficiencies in Location and Consumption

Tax benefits to owner-occupied housing provide incentives to consume housing, offsetting weaker disincentives of the property tax. These benefits also help counter the penalty federal taxes impose on households who work in productive high-wage areas, but reinforce incentives to consume local amenities. We simulate the effects of these benefits in a parameterized model, and determine the consequences of various tax reforms. Reductions in housing tax benefits generally increase efficiency in consumption, but reduce efficiency in location decisions, unless they are accompanied by tax rate reductions. The most efficient policy would eliminate most tax benefits to housing and index taxes to local wage levels

SU(2) nonstandard bases: the case of mutually unbiased bases

This paper deals with bases in a finite-dimensional Hilbert space. Such a space can be realized as a subspace of the representation space of SU(2) corresponding to an irreducible representation of SU(2). The representation theory of SU(2) is reconsidered via the use of two truncated deformed oscillators. This leads to replace the familiar scheme {j^2, j_z} by a scheme {j^2, v(ra)}, where the two-parameter operator v(ra) is defined in the enveloping algebra of the Lie algebra su(2). The eigenvectors of the commuting set of operators {j^2, v(ra)} are adapted to a tower of chains SO(3) > C(2j+1), 2j integer, where C(2j+1) is the cyclic group of order 2j+1. In the case where 2j+1 is prime, the corresponding eigenvectors generate a complete set of mutually unbiased bases. Some useful relations on generalized quadratic Gauss sums are exposed in three appendices.Comment: 33 pages; version2: rescaling of generalized Hadamard matrices, acknowledgment and references added, misprints corrected; version 3: published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA/ (22 pages

Gravimetric maps of the Central African Republic

Gravimetric maps of the Central African Republic are described including a map of Bouguer anomalies at 1/1,000,000 in two sections (eastern sheet, western sheet) and a map, in color, of Bouguer anomalies at 1/2,000,000. Instrumentation, data acquisition, calibration, and data correction procedures are discussed

On the force fields which are homogeneous of degree −3-3

The dynamics defined by a force field which is positively homogeneous of degree $-3$ can always be reduced, by simply constraining it. The dimension of the phase space is reduced by two dimensions, while it may only be reduced by one dimension if the degree of homogeneity is different from $-3$. This remark is an elegant foundation of Appell's projective dynamics. We show how it relates to Kn\"orrer's remark on the correspondence between the Neumann potential on a sphere and the geodesic motion on an ellipsoid.Comment: 6 pages, 1 figur

The isotropic lines of Z_{d}^{2}

We show that the isotropic lines in the lattice Z_{d}^{2} are the Lagrangian submodules of that lattice and we give their number together with the number of them through a given point of the lattice. The set of isotropic lines decompose into orbits under the action of SL(2,Z_d). We give an explicit description of those orbits as well as their number and their respective cardinalities. We also develop two group actions on the group \Sigma_{D}(M) related to the topic.Comment: 10 page

What Are Cities Worth? Land Rents, Local Productivity, and the Capitalization of Amenity Values

An equilibrium model predicts that inter-city differences in firm productivity, and the full value of local amenities cannot be inferred without land values. These may be inferred from ordinary wage and housing-cost data using the housing-cost function if housing-sector productivity is constant. A calibrated model predicts how quality-of-life and production amenities are capitalized differently into land values, wages, housing costs, and federal-tax payments. The total value of these amenities are estimated across U.S. cities. Wages and housing costs are driven more by productivity than quality-of-life differences. The most productive and valuable cities are typically coastal, sunny, mild, educated and large.

Partisan Representation in Congress and the Geographic Distribution of Federal Funds

In a two-party legislature, districts represented by the majority may receive greater funds if majority-party legislators have greater proposal power or disproportionately form coalitions with each other. Funding types received by districts may depend on their legislators’ party-identity when party preferences differ. Estimates from the United States – using fixed-effect and regression-discontinuity designs – indicate that states represented by members of Congress in the majority receive greater federal grants, especially in transportation, and defense spending. States represented by Republicans receive more for defense and transportation than those represented by Democrats; the latter receive more spending for education and urban development.

Dynamic Estimation of Health Expenditure: A new approach for simulating individual expenditure

This study compares estimates of outpatient expenditure computed with different models. Our aim is to predict annual health expenditures. We use a French panel dataset over a six year period (2000-2006) for 7112 individuals. Our article is based on the estimations of five different models. The first model is a simple two part model estimated in cross section. The other models (models 2 to 5) are estimated with selection models (or generalized tobit models). Model 2 is a basic sample selection model in cross section. Model 3 is similar to model 2, but takes into account the panel dimension. It includes constant unobserved heterogeneity to deal with state dependency. Model 4 is a dynamic sample selection model (with lagged adjustement), while in model 5, we take into account the possible heteroskedasticity of residuals in the dynamic model. We find that all the models have the same properties in the cross section dimension (distribution, probability of health care use by gender and age, health expenditure by gender and age) but model 5 gives better results reflecting the temporal correlation with health expenditure. Indeed, the retransformation of predicted log transformed expenditures in homoscedastic models (models 1 to 4) generates very poor temporal correlation for " heavy consumers ", although the data show the contrary. Incorporation of heteroskedasticity gives better results in terms of temporal correlation.Health econometrics, expenditures, panel data, selection models