Asymptotics for Hermite-Pade rational approximants for two analytic functions with separated pairs of branch points (case of genus 0)

We investigate the asymptotic behavior for type II Hermite-Pade approximation to two functions, where each function has two branch points and the pairs of branch points are separated. We give a classification of the cases such that the limiting counting measures for the poles of the Hermite-Pade approximants are described by an algebraic function of order 3 and genus 0. This situation gives rise to a vector-potential equilibrium problem for three measures and the poles of the common denominator are asymptotically distributed like one of these measures. We also work out the strong asymptotics for the corresponding Hermite-Pade approximants by using a 3x3 Riemann-Hilbert problem that characterizes this Hermite-Pade approximation problem.Comment: 102 pages, 31 figure

Institutions and Multinational Ownership Strategy

This paper examines the impact of institutions on a multinational firm’s ownership strategy. We develop an international joint venture (IJV) model in which a multinational firm and its local partner both can undertake costly ex post actions to increase their revenue share specified by the ex ante IJV contract. The model captures the effects of two institutional features on the optimal IJV ownership structure: contract enforceability and cronyism. We introduce the IJV model into an industry equilibrium framework to analyze the impact of institutions on a multinational firm’s choice between forming an IJV or setting up a wholly-owned subsidiary. Ce papier examine l'impact des institutions sur la stratégie de propriété d’une entreprise multinationale. Nous développons un modèle de coentreprise internationale dans lequel une entreprise étrangère et son partenaire local peuvent ex post entreprendre des actions coûteuses pour augmenter leur part de revenus indiquée dans le contrat de coentreprise. Le modèle analyse les impacts de deux caractéristiques institutionnelles sur la structure de propriété optimale : le renforcement du contrat et le copinage. Nous introduisons le modèle de coentreprise dans un modèle d'équilibre général pour analyser l'impact des institutions sur le mode d’entrée des entreprises multinationales.liability of foreignness, international joint venture, contract enforceability, cronyism, coentreprise internationale, renforcement du contrat, copinage

An Assessment of the KDICP and MDICP Data Quality

This paper evaluates the quality of the data collected as part of the Kenya and Malawi Diffusion and Ideational Change Projects, two longitudinal household surveys that examine the role of social networks in influencing attitudes and behavior regarding family size, family planning, and HIV/AIDS in, respectively, rural Kenya and Malawi. We investigate three sources of non-sampling error: interviewer effects, response reliability and sample attrition, highlighting the interaction between them, and paying particular attention to their implications for AIDS-related behavioral research.agriculture, attrition, data quality, family planning, interviewer effects, interviews, Kenya, Malawi, measurement, measurements, reliability

Quadratic Hermite-Pade approximation to the exponential function: a Riemann-Hilbert approach

We investigate the asymptotic behavior of the polynomials p, q, r of degrees n in type I Hermite-Pade approximation to the exponential function, defined by p(z)e^{-z}+q(z)+r(z)e^{z} = O(z^{3n+2}) as z -> 0. These polynomials are characterized by a Riemann-Hilbert problem for a 3x3 matrix valued function. We use the Deift-Zhou steepest descent method for Riemann-Hilbert problems to obtain strong uniform asymptotics for the scaled polynomials p(3nz), q(3nz), and r(3nz) in every domain in the complex plane. An important role is played by a three-sheeted Riemann surface and certain measures and functions derived from it. Our work complements recent results of Herbert Stahl.Comment: 60 pages, 13 figure

Security of Quantum Key Distribution with Coherent States and Homodyne Detection

We assess the security of a quantum key distribution protocol relying on the transmission of Gaussian-modulated coherent states and homodyne detection. This protocol is shown to be equivalent to a squeezed state protocol based on a CSS code construction, and is thus provably secure against any eavesdropping strategy. We also briefly show how this protocol can be generalized in order to improve the net key rate.Comment: 7 page

Input Specificity and Global Sourcing

This paper investigates the role of productivity on a firm’s organizational choice. We expand Antràs and Helpman (2004) by allowing heterogeneous firms to choose between adopting specific and generic inputs. In input-intensive industries, firms face a trade-off between the lower productivity of generic inputs and the reduced hold-up friction of generic outsourcing. We demonstrate that the hold-up friction under generic outsourcing increases with a firm’s productivity. This implies that: (i) high productivity firms choose ideal outsourcing to the South, (ii) medium productivity firms choose generic outsourcing to the South, (iii) low productivity firms choose generic outsourcing to the North. Cet article étudie le rôle de la productivité sur les choix organisationnels des entreprises. Nous élargissons l’étude d’Antràs et Helpman (2004) en permettant aux entreprises hétérogènes de choisir entre l’adoption d’intrants spécifiques ou génériques. Au sein des industries caractérisées par une forte utilisation d’intrants, les entreprises font face à un compromis entre une productivité réduite liée aux intrants génériques et un problème de hold-up moindre découlant de l’impartition générique. Nous démontrons que le problème de hold-up lié à l’impartition générique augmente selon la productivité d’une entreprise. Ce qui implique que : les entreprises dont le taux de productivité est élevé choisissent l’impartition optimale au Sud, (ii) les entreprises dont le taux de productivité est moyen choisissent l’impartition générique au Sud, (iii) les entreprises dont le taux de productivité est bas choisissent l’impartition générique au Nord.input specificity, outsourcing, firm heterogeneity, incomplete contracts, hold-up problem, spécificité des intrants, impartition, hétérogénéité des entreprises, incomplétude des contrats, problèmes de hold-up.

Unique positive solution for an alternative discrete Painlevé I equation

We show that the alternative discrete Painleve I equation has a unique solution which remains positive for all n >0. Furthermore, we identify this positive solution in terms of a special solution of the second Painleve equation involving the Airy function Ai(t). The special-function solutions of the second Painleve equation involving only the Airy function Ai(t) therefore have the property that they remain positive for all n>0 and all t>0, which is a new characterization of these special solutions of the second Painlevé equation and the alternative discrete Painlevé I equation

Strong asymptotics for Cauchy biorthogonal polynomials with application to the Cauchy two--matrix model

We apply the nonlinear steepest descent method to a class of 3x3 Riemann-Hilbert problems introduced in connection with the Cauchy two-matrix random model. The general case of two equilibrium measures supported on an arbitrary number of intervals is considered. In this case, we solve the Riemann-Hilbert problem for the outer parametrix in terms of sections of a spinorial line bundle on a three-sheeted Riemann surface of arbitrary genus and establish strong asymptotic results for the Cauchy biorthogonal polynomials.Comment: 31 pages, 12 figures. V2; typos corrected, added reference