Panel Data Analysis of the Time-Varying Determinants of Corruption

There is a long history of models attempting to identify the causes of corruption, yet empirical analysis is complicated. Not only is data difficult to obtain and often available only for few countries and a limited number of years, but such estimation involves inherent complexities. This paper focuses on the use of panel data techniques to better identify factors that affect bureaucratic corruption. Furthermore, this paper identifies an endogeneity problem which arises in the analysis of the causes of corruption, and a new instrumental variable is proposed to solve it. To help in this endeavor, a data set is employed which provides information for as many as 135 countries over a span of sixteen years. Results show that neglecting the endogeneity problem leads to severely biased results. Using panel data techniques reveals that the availability of rents is a crucial determinant of corruption and that previous research may have underestimated the economic significance of rents on corruption. Furthermore, corruption is shown to be procyclical. Depuis longtemps, des modèles sont utilisés dans le but de déterminer les causes de la corruption. Toutefois, l’analyse empirique demeure complexe. Qui plus est, les données sont difficiles à recueillir et couvrent souvent un nombre restreint de pays et une période limitée. Ce genre d’évaluation présente aussi des complexités inhérentes. Le présent document met l’accent sur le recours à des techniques de données de panels dans le but de mieux connaître les facteurs qui influent sur la corruption bureaucratique. En outre, cette analyse souligne le problème d’endogénéité qui ressort de l’analyse des causes de la corruption et propose une nouvelle variable instrumentale permettant de contrer celui-ci. Pour faciliter la démarche, ce document utilise un ensemble de données fournissant des renseignements sur au moins 135 pays et pour une période de seize ans. Les résultats indiquent que si le problème d’endogénéité n’est pas pris en compte, les résultats sont sérieusement biaisés. De plus, la corruption est décrite comme étant procyclique.corruption, endogeneity, income, rents, corruption, endogénéité

Simple recurrence formulas to count maps on orientable surfaces

We establish a simple recurrence formula for the number $Q_g^n$ of rooted orientable maps counted by edges and genus. We also give a weighted variant for the generating polynomial $Q_g^n(x)$ where $x$ is a parameter taking the number of faces of the map into account, or equivalently a simple recurrence formula for the refined numbers $M_g^{i,j}$ that count maps by genus, vertices, and faces. These formulas give by far the fastest known way of computing these numbers, or the fixed-genus generating functions, especially for large $g$. In the very particular case of one-face maps, we recover the Harer-Zagier recurrence formula. Our main formula is a consequence of the KP equation for the generating function of bipartite maps, coupled with a Tutte equation, and it was apparently unnoticed before. It is similar in look to the one discovered by Goulden and Jackson for triangulations, and indeed our method to go from the KP equation to the recurrence formula can be seen as a combinatorial simplification of Goulden and Jackson's approach (together with one additional combinatorial trick). All these formulas have a very combinatorial flavour, but finding a bijective interpretation is currently unsolved.Comment: Version 3: We changed the title once again. We also corrected some misprints, gave another equivalent formulation of the main result in terms of vertices and faces (Thm. 5), and added complements on bivariate generating functions. Version 2: We extended the main result to include the ability to track the number of faces. The title of the paper has been changed accordingl

State-dependent pricing, inflation, and welfare in search economies

This paper investigates the welfare effects of inflation in economies with search frictions and menu costs. We first analyze an economy where there is no transaction demand for money balances: Money is a mere unit of account. We determine a condition under which price stability is optimal and a condition under which positive inflation is desirable. We relate these conditions to a standard efficiency condition for search economies. Second, we consider a related economy in which there is a transaction role for money. In the absence of menu costs, the Friedman rule is optimal. In the presence of menu costs, the optimal inflation rate is negative for all our numerical examples. A deviation from the Friedman rule can be optimal depending on the extent of the search externalities.Inflation (Finance) ; Money ; Monetary policy

An apertureless near-field microscope for fluorescence imaging

We describe an apertureless near field microscope for imaging fluorescent samples. Optical contrast is generated by exploiting fluorescent quenching near a metallized atomic force microscope tip. This microscope has been used to image fluorescent latex beads with subdiffraction limit resolution. The use of fluorescence allows us to prove that the contrast mechanism is indeed spectroscopic in origin

Post-Newtonian prediction for the (2,2) mode of the gravitational wave emitted by compact binaries

We present our 3.5PN computation of the (2,2) mode of the gravitational wave amplitude emitted by compact binaries, on quasi-circular orbits and in the absence of spins. We use the multipolar post-Newtonian wave generation formalism, extending and building on previous works which computed the 3PN order. This calculation required the extension of the multipolar post-Minkowskian algorithm, as well as the computation of the mass source quadrupole at 3.5PN order. Our result will allow more accurate comparisons to numerical relativity, and is a first step towards the computation of the full 3.5PN waveform amplitude, which would improve the estimation of the source parameters by gravitational wave detectors.Comment: 5 pages; proceeding of the 9th LISA Symposium, Pari

The third and a half post-Newtonian gravitational wave quadrupole mode for quasi-circular inspiralling compact binaries

We compute the quadrupole mode of the gravitational waveform of inspiralling compact binaries at the third and a half post-Newtonian (3.5PN) approximation of general relativity. The computation is performed using the multipolar post-Newtonian formalism, and restricted to binaries without spins moving on quasi-circular orbits. The new inputs mainly include the 3.5PN terms in the mass quadrupole moment of the source, and the control of required subdominant corrections to the contributions of hereditary integrals (tails and non-linear memory effect). The result is given in the form of the quadrupolar mode (2,2) in a spin-weighted spherical harmonic decomposition of the waveform, and may be used for comparison with the counterpart quantity computed in numerical relativity. It is a step towards the computation of the full 3.5PN waveform, whose knowledge is expected to reduce the errors on the location parameters of the source.Comment: 19 pages, 1 figure; minor corrections, including some rephrasing in the introduction and in section III