The Econometrics of DSGE Models

In this paper, I review the literature on the formulation and estimation of dynamic stochastic general equilibrium (DSGE) models with a special emphasis on Bayesian methods. First, I discuss the evolution of DSGE models over the last couple of decades. Second, I explain why the profession has decided to estimate these models using Bayesian methods. Third, I briefly introduce some of the techniques required to compute and estimate these models. Fourth, I illustrate the techniques under consideration by estimating a benchmark DSGE model with real and nominal rigidities. I conclude by offering some pointers for future research.DSGE Models, Likelihood Estimation, Bayesian Methods

From nominal to higher-order rewriting and back again

We present a translation function from nominal rewriting systems (NRSs) to combinatory reduction systems (CRSs), transforming closed nominal rules and ground nominal terms to CRSs rules and terms, respectively, while preserving the rewriting relation. We also provide a reduction-preserving translation in the other direction, from CRSs to NRSs, improving over a previously defined translation. These tools, together with existing translations between CRSs and other higher-order rewriting formalisms, open up the path for a transfer of results between higher-order and nominal rewriting. In particular, techniques and properties of the rewriting relation, such as termination, can be exported from one formalism to the other.Comment: 41 pages, journa

Arqueología de una aldea medieval y su espacio agrario: Villanueva de Santo Adriano (Asturias, noroeste de la península Ibérica)

En este artículo se presentan los resultados del estudio arqueológico de una aldea de origen medieval, aún habitada, y su espacio agrario, localizados en Asturias (noroeste de la península Ibérica). Con esta investigación se ha buscado dar respuesta a tres cuestiones que a día de hoy continuaban sin ser precisadas en esta área de montaña: ¿cuándo se produce la génesis de las aldeas?, ¿cómo? y, finalmente, ¿cómo se han ido transformando y evolucionado a través del tiempo? Para alcanzar estos objetivos se han aplicando las metodologías tradicionales de la arqueología del paisaje, la historia rural, el estudio de la toponimia y la documentación, combinándolas con la datación y análisis diacrónico que permiten la arqueología de excavación, los datos paleoambientales y los estudios sedimentológicos. Todo el territorio aldeano se analizó como un único objeto de estudio, incluidas las áreas de producción agraria, que pasaron a formar parte prioritaria de la agenda de investigación. Esta aproximación nos ha permitido reconstruir la historia de una aldea y sus terrazgos desde su momento de formación en la Alta Edad Media (siglos viii-xi) hasta el presente, e identificar los diferentes momentos de estabilidad y cambio en su paisaje. Creemos que más intervenciones como la desarrollada nos permitirán disponer de datos para la comparación y la creación de marcos generales de reflexión que conecten nuestra arqueología agraria con las discusiones a escala europea ya iniciadas décadas atrás.This article examines the causes of the establishment and temporal evolution of a medieval village in the mountainous region of Asturias, in the north-wester n Iber ian Peninsula. A variety of methods were used for this purpose, including landscape archaeolog y, r ural histor y, the study of place names and written documents, combined with archaeolog ical excavation, paleo-environmental analysis and sedimentological studies. A priority research point included the village surroundings that had been used for agricultural production; the whole area was analysed as one single object of study. This approach provided the possibility of identifying the various moments of stability and change in the landscape along with a reconstruction of the histor y of this still inhabited village and its agr icultural milieu beginning in the Early Middle Ages (eighth to eleventh centuries). Further research along the lines developed here should provide data for comparison and connect this agricultural archaeology research with the broader European framework of discussion launched in past decades

Invariant versus classical quartet inference when evolution is heterogeneous across sites and lineages

One reason why classical phylogenetic reconstruction methods fail to correctly infer the underlying topology is because they assume oversimplified models. In this paper we propose a topology reconstruction method consistent with the most general Markov model of nucleotide substitution, which can also deal with data coming from mixtures on the same topology. It is based on an idea of Eriksson on using phylogenetic invariants and provides a system of weights that can be used as input of quartet-based methods. We study its performance on real data and on a wide range of simulated 4-taxon data (both time-homogeneous and nonhomogeneous, with or without among-site rate heterogeneity, and with different branch length settings). We compare it to the classical methods of neighbor-joining (with paralinear distance), maximum likelihood (with different underlying models), and maximum parsimony. Our results show that this method is accurate and robust, has a similar performance to ML when data satisfies the assumptions of both methods, and outperforms all methods when these are based on inappropriate substitution models or when both long and short branches are present. If alignments are long enough, then it also outperforms other methods when some of its assumptions are violated.Comment: 32 pages; 9 figure

Gevrey expansions of hypergeometric integrals II

We study integral representations of the Gevrey series solutions of irregular hypergeometric systems under certain assumptions. We prove that, for such systems, any Gevrey series solution, along a coordinate hyperplane of its singular support, is the asymptotic expansion of a holomorphic solution given by a carefully chosen integral representation.Comment: 27 pages, 2 figure

A General Model of Bilateral Migration Agreements

Unilateral migration policies impose externalities on other countries. In order to try to internalize these externalities, countries sign bilateral migration agreements. One element of these agreements is the emphasis on enforcing migration policies: immigrant-receiving countries agree to allow more immigrants from their emigrant-sending partner if they cooperate in enforcing their migration policy at the border. I present a simple theoretical model that justifies this behavior in a two-country setting with welfare maximizing governments. These governments establish migration quotas that need to be enforced at a cost. I prove that uncoordinated migration policies are inefficient. Both countries can improve welfare by exchanging a more "generous" migration quota for expenditure on enforcement policy. Contrary to what could be expected, this result does not depend on the enforcement technology that both countries employ.international migration, cooperation, migration policy