933 research outputs found
How frequently do consumer prices change in Austria? Evidence from micro CPI data
Based on individual price records collected for the computation of the Austrian CPI, average frequencies of price changes and durations of price spells are estimated to characterize price setting in Austria. Depending on the estimation method, prices are unchanged for 10 to 14 months on average. We find strong heterogeneity across sectors and products. Price increases occur only slightly more often than price decreases. The typical size of a price increase (decrease) is 11 (15) percent. The aggregate hazard function of prices is decreasing with time. Besides heterogeneity across products and price setters, this is due to oversampling of products with a high frequency of price changes. Accounting for unobserved heterogeneity in estimating the probability of a price change with a fixed-effects logit model, we find a positive effect of the duration of a price spell. During the Euro cash changeover the probability of price changes was higher. JEL Classification: C41, D21, E31, L11consumer prices, duration of price spells, frequency and synchronization of price changes, sticky prices
On an air quality and odor modeling system for CMPC Celulose Riograndense
The present work is part of the research project that aims to create an automated system for the evaluation of air pollution and odour for CMPC CELULOSE RIOGRANDENSE. Initially, three different ways of initializing the CALPUFF model (one of the models under evaluation to compose the system) were evaluated. The results when compared with observational data on air quality suggest the need for a validation of the boundary conditions and turbulent scale parameters in the hourly time representation when CALPUFF is the model being used. The choice was not random, but based on three quantities that impose physical affinity to micrometeorological data. The surface roughness, the albedo and the Bowen ratio. Changes in these quantities were imposed during pre-processing of AERMET, which established the quantities of interest in a simulation of dispersion of pollutants. After this alternative the results become more representative for the atmospheric dispersion process. The monthly and annual representation of the CALPUFF model is satisfactory without validation procedure
Patterns and Determinants of Price Changes: Analysing Individual Consumer Prices in Austria
We provide empirical evidence on the degree and characteristics of price rigidity in Austria by estimating the average frequency of price changes and the duration of price spells from a large data set of individual price records collected for the computation of the Austrian CPI
Self-reciprocal fermion mass ratios from massless QED with curved momentum space
The present investigation is an attempt to understand the fermion mass ratios in the framework of QED of charged fermions without a bare mass. Since QED of massless charged fermions is invariant under the dilatation transformation, this symmetry has to be spontaneously broken to obtain massive fermions. In the proposed model we combine a mass-scale normalisation with the renormalisation procedure, assuming the fermion momentum space being a four-dimensional one-shell hyperboloid embedded in a five-dimensional space. The hyperboloid constrains the allowed fermion field solutions. We construct the theory in the conventional way using equal time anti-commutator and the Lagrangian formalism. Starting from the Dyson–Schwinger equation for fermion propagator in the Landau gauge, we derive the fermion mass function and self-reciprocal solutions for the mass ratios, which are independent of any constant
Buchonomyia thienemanni n. gen. n. sp. Chironomidenstudien IV (Diptera: Chironomidae).
Nomenklatorische Handlungenthienemanni Fittkau, 1955 (Buchonomyia), spec. n.Buchonomyia Fittkau, 1955 (Chironomidae), gen. n.Nomenclatural Actsthienemanni Fittkau, 1955 (Buchonomyia), spec. n.Buchonomyia Fittkau, 1955 (Chironomidae), gen. n
- …