Rare Decays in LHCb

The rare B decays Bs(d)-->\mu\mu, B-->K*\mu\mu and Bs-->\phi\gamma are studied using up to \sim 0.41 fb^{-1} of pp collisions at \sqrt{s} = 7 TeV collected by the \lhcb experiment in 2010 and 2011. A search for the decays Bs(d)-->\mu\mu, is performed with 0.41 fb^{-1} . The absence of significant signal leads to BR(Bs-->\mu\mu\mu\mu<3.2 x 10^{-9} at 95% confidence level. The forward-backward asymmetry, fraction of longitudinal polarization and differential branching fraction of B-->K*\mu\mu, as a function of dimuon invariant mass, are measured in 0.31 fb^{-1}. The ratio of branching ratios of the radiative B decays B--> K*\gamma and Bs-->\phi\gamma h as been measured using 0.34fb^{-1}. The obtained value for the ratio is 1.52 \pm 0.14 (stat) \pm 0.10 (syst) \pm 0.12 (f_s/f_d). Using the HFAG value for BR(Bd --> K^*\gamma), BR(Bs-->\phi\gamma) has been found to be (2.8 \pm 0.5)\times 10^{-5}.Comment: "Presented at the 2011 Hadron Collider Physics symposium (HCP-2011), Paris, France, November 14-18 2011, 4 pages, 2 figuras.

The optimal provision of public inputs in a second best scenario

This paper provides a simple general equilibrium model with productive public spending and distorting taxes. The optimal conditions for the provision of public inputs are obtained under different tax systems. Also we discuss which factors affect the marginal cost of public funds.

How does a fisacl reform affect elasticities of income tax revenues? the case os Spain, 2003-2008

This paper estimates the extent to which an exogenous change in income affects income tax revenues. We focus on the case of Spain over the period 2003-2008, as income tax there underwent a substantial reform in 2007. Using both an analytical method and a numerical simulation, we find a significant increase in aggregate income tax elasticities from 1.4 for 2003-2003 to around 1.8 for 2007-2008. The sensitivity of results to the presence of housing tax credits, non-equiproportional variations in income, changes in income inequality and fiscal drag is also considered.income tax elasticity; progressivity; tax rates; tax credits

Ad Valorem Taxes and the Fiscal Gap in Federations

This paper investigates the implications of vertical fiscal externalities for the optimal federal tax and the sign of fiscal gap in the presence of ad valorem taxation. It is shown that the federal government can always achieve the second-best optimum for public good provision. The sign of the fiscal gap is, in general, ambiguous. The consequence of this is that a precise evaluation of the fiscal gap requires an explicit consideration of the underlying fundamentals of the federal economy.Ad valorem taxes; fiscal gap; externalities; fiscal federalism

Can Labor Market Imperfections Cause Overprovision of Public Inputs?

In a model where trade unions dominate the labor market, a relationship is derived between the rate of unemployment and the provision of a public input in the production. This relationship implies that for conventional rates of unemployment, the public input will be overprovided compared to the first-best level.Public Inputs, Trade Unions.

Document Distance for the Automated Expansion of Relevance Judgements for Information Retrieval Evaluation

This paper reports the use of a document distance-based approach to automatically expand the number of available relevance judgements when these are limited and reduced to only positive judgements. This may happen, for example, when the only available judgements are extracted from a list of references in a published review paper. We compare the results on two document sets: OHSUMED, based on medical research publications, and TREC-8, based on news feeds. We show that evaluations based on these expanded relevance judgements are more reliable than those using only the initially available judgements, especially when the number of available judgements is very limited.Comment: SIGIR 2014 Workshop on Gathering Efficient Assessments of Relevanc