De lo real a lo imaginario. Aproximación a la flora ibérica durante la Edad del Hierro

“From the real to the imagery” is the translation of the project’s title we present in this paper. Our main goal is the study of the Iberian Iron Age flora from several points of view in order to come close to the use and the simbolism of plants among the ancient societies, specially the Iberian Culture. The method we use is a combination of a paleobotanical approach, based on palinology, anthracology and paleocarpology, together with an iconographic one. Then, we record all the representations of plants on pottery, stone sculpture, metallic objects and coins. All these data are catalogued taking in to account the context and chronology of the archaeological remains we are dealing with. The aim of this research project is to create a database of the used and known plants among the Iberians, to reconstruct the possible uses (“the real”) and the images of plants represented on the artefacts (“the imagery”). This paper offers preliminary results of our method by presenting an analytical example based on two species: the poppy (Papaver sp.) and the palm tree (Phoenix datylifera L.).“De lo real a lo imaginario” es el título de un proyecto cuyo objetivo es hacer un estudio de la flora de los iberos desde distintos puntos de vista con el fin de aproximarnos al uso y simbolismo de las plantas por parte de las sociedades antiguas. Para ello se va a combinar una visión estrictamente paleobotánica, basada en estudios palinológicos, antracológicos y paleocarpológicos, con la iconográfica, recogiendo todas las representaciones de plantas que aparecen en cerámica, escultura en piedra, objetos metálicos y monedas. Todos los datos se catalogan teniendo en cuenta su contexto y cronología. Con ello se pretende elaborar un catálogo de plantas conocidas y utilizadas, en diferentes contextos, con todos los usos posibles (lo real) y las imágenes de plantas recogidas en diversos soportes (lo imaginario). Como ejemplo, se presenta el estudio realizado sobre dos plantas: la adormidera (Papaver sp.) y la palmera (Phoenix datylifera L.)

The Dynamic Striated Metropolis-Hastings Sampler for High-Dimensional Models

Having efficient and accurate samplers for simulating the posterior distribution is crucial for Bayesian analysis. We develop a generic posterior simulator called the "dynamic striated Metropolis-Hastings (DSMH)" sampler. Grounded in the Metropolis-Hastings algorithm, it draws its strengths from both the equienergy sampler and the sequential Monte Carlo sampler by avoiding the weaknesses of the straight Metropolis-Hastings algorithm as well as those of importance sampling. In particular, the DSMH sampler possesses the capacity to cope with incredibly irregular distributions that are full of winding ridges and multiple peaks and has the flexibility to take full advantage of parallelism on either desktop computers or clusters. The high-dimensional application studied in this paper provides a natural platform to put to the test generic samplers such as the DSMH sampler

Methods for Computing Marginal Data Densities from the Gibbs Output

We introduce two new methods for estimating the Marginal Data Density (MDD) from the Gibbs output, which are based on exploiting the analytical tractability condition. Such a condition requires that some parameter blocks can be analytically integrated out from the conditional posterior densities. Our estimators are applicable to densely parameterized time series models such as VARs or DFMs. An empirical application to six-variate VAR models shows that the bias of a fully computational estimator is sufficiently large to distort the implied model rankings. One estimator is fast enough to make multiple computations of MDDs in densely parameterized models feasible

Evidence on a Real Business Cycle Model with Neutral and Investment-Specific Technology Shocks Using Bayesian Model Averaging

The empirical support for a real business cycle model with two technology shocks is evaluated using a Bayesian model averaging procedure. This procedure makes use of a finite mixture of many models within the class ofvector autoregressive (VAR) processes. The linear VAR model is extendedto permit cointegration, a range of deterministic processes, equilibrium restrictions and restrictions on long-run responses to technology shocks. Wefind support for a number of the features implied by the real business cyclemodel. For example, restricting long run responses to identify technologyshocks has reasonable support and important implications for the short runresponses to these shocks. Further, there is evidence that savings and investment ratios form stable relationships, but technology shocks do not accountfor all stochastic trends in our system. There is uncertainty as to the mostappropriate model for our data, with thirteen models receiving similar support, and the model or model set used has signficant implications for theresults obtained

Post-2020 climate agreements in the major economies assessed in the light of global models

Integrated assessment models can help in quantifying the implications of international climate agreements and regional climate action. This paper reviews scenario results from model intercomparison projects to explore different possible outcomes of post-2020 climate negotiations, recently announced pledges and their relation to the 2 °C target. We provide key information for all the major economies, such as the year of emission peaking, regional carbon budgets and emissions allowances. We highlight the distributional consequences of climate policies, and discuss the role of carbon markets for financing clean energy investments, and achieving efficiency and equity

Identification of Financial Factors in Economic Fluctuations

We estimate demand, supply, monetary, investment and financial shocks in a VAR identified with a minimum set of sign restrictions on US data. We find that financial shocks are major drivers of fluctuations in output, stock prices and investment but have a limited effect on inflation. In a second step we disentangle shocks originating in the housing sector, shocks originating in credit markets and uncertainty shocks. In the extended set-up financial shocks are even more important and a leading role is played by housing shocks that have large and persistent effects on output.publishedVersio