Search results for "Persistence"
showing 10 items of 243 documents
One swallow does not make a summer: episodes and persistence in high growth
2021
This paper analyzes firms’ episodes (spells) of high growth (HG) using a sample of Spanish manufacturing firms observed over two decades. The use of duration models allows us to investigate the following: (i) the probability of experiencing HG episodes, (ii) persistence in HG, and (iii) the determinants of the transitions in and out of the HG state and whether their impact varies over the business cycle. We find that about half of the firms experience at least one HG episode, but they seldom experience more than one. Moreover, high-growth status is rarely repeated due to high first-year selection. Yet, in subsequent years beyond the first one, the hazard rate from HG status falls substantia…
Nonlinear GARCH models for highly persistent volatility
2005
In this paper we study new nonlinear GARCH models mainly designed for time series with highly persistent volatility. For such series, conventional GARCH models have often proved unsatisfactory because they tend to exaggerate volatility persistence and exhibit poor forecasting ability. Our main emphasis is on models that are similar to previously introduced smooth transition GARCH models except for the novel feature that a lagged value of conditional variance is used as the transition variable. This choice of the transition variable corresponds to the idea that high persistence in conditional variance is related to relatively infrequent changes in regime. U sing the theory of Markov chains w…
Resolving reading disability : Childhood predictors and adult-age outcomes
2018
We examined frequency of adult-age reading disability (RD) and its childhood predictors among 48 adults (20 to 39 years) with documented childhood RD, and contrasted their cognitive skills, education, and employment with 37 matched controls. Among individuals with childhood RD, more than half had improved in their reading fluency to the level where the set criterion for adult-age RD was not met anymore. More fluent rapid naming, less severe childhood RD, and multiple support providers in childhood together predicted improvement of reading fluency. More fluent naming differentiated the childhood RD participants whose reading fluency had improved by adult-age from those participants whose RD …
Persistence of low back pain reporting among a cohort of employees in a metal corporation: A study with 5-, 10-, and 28-year follow-ups
2005
Low back pain (LBP) is a common symptom among adults but little is known about its persistence over time in defined populations. The aim of this study was to examine the persistence of LBP among a cohort of industrial employees studied in four successive surveys during a total of 28 years. Cross-tabulations and logistic regression was used to estimate the interdependence of LBP occurrence at the surveys. At baseline, 54% of the subjects reported local LBP and 25% LBP radiating to the lower limb(s). Persistent or recurrent LBP was common. Of those with LBP at baseline, 75, 73, and 88% reported it also at the 5-, 10- or 28-year follow-up, respectively. Of those with radiating pain, 66, 65, an…
General framework for testing Poisson-Voronoi assumption for real microstructures
2020
Modeling microstructures is an interesting problem not just in Materials Science but also in Mathematics and Statistics. The most basic model for steel microstructure is the Poisson-Voronoi diagram. It has mathematically attractive properties and it has been used in the approximation of single phase steel microstructures. The aim of this paper is to develop methods that can be used to test whether a real steel microstructure can be approximated by such a model. Therefore, a general framework for testing the Poisson-Voronoi assumption based on images of 2D sections of real metals is set out. Following two different approaches, according to the use or not of periodic boundary conditions, thre…
Persistence of temperature and precipitation: from local to global anomalies
2021
Using detrended fluctuation analysis (DFA) we find that all continents are persistent in temperature. The scaling exponents of the southern hemisphere (SH) continents, i.e., South America (0.77) and Oceania (0.72) are somewhat higher than scaling exponents of Europe (0.70), Asia (0.69) and North America (0.64), but the scaling of Africa is by far the highest (0.86). The reason for this is the location of Africa near the equator. The scaling exponents of the precipitation are much smaller, i.e. between 0.55 (Europe) and 0.68 (North America). The scaling exponent of Europe is near that of the random noise (0.5), while the other continents are slightly persistent in precipitation. We also show…
Exports of Spanish manufacturing firms and financial constraints
2020
We investigate the role of financial constraints on firms’ exporting behavior, including firms’ export decision, export intensity, firms starting to export decision, and exports persistence. Our financial constraints variable is a synthetic variable that summarizes information on different dimensions such as total assets, profitability, liquidity, solvency, repaying ability, and (new in this type of analyses) the cost of external financing. Using data on Spanish manufacturing for the period 1992–2014, we find evidence supporting that financial health is relevant to explain small and medium-sized enterprises (SMEs) exporting decisions and starting to export decisions but not those of large …
Gastrointestinal symptoms and association with medication use patterns, adherence, treatment satisfaction, quality of life, and resource use in osteo…
2016
The Medication Use Patterns, Treatment Satisfaction, and Inadequate Control of Osteoporosis Study (MUSIC-OS) is a prospective, observational study of women with osteoporosis in Europe and Canada. At baseline, patients with gastrointestinal symptoms reported lower adherence to osteoporosis treatment, treatment satisfaction, and health-related quality of life, than those without gastrointestinal symptoms. INTRODUCTION: The aim of the study was to examine gastrointestinal (GI) symptoms and the association between GI symptoms and treatment adherence, treatment satisfaction, and health-related quality of life (HRQoL) among osteoporotic women in Europe and Canada. METHODS: Baseline results are re…
Does persistence in using R&D tax credits help to achieve product innovations?
2021
Despite the generosity of its tax system, Spain is far from EU countries in terms of R&D spending and innovation outcomes. A policy instrument commonly used to foster firms’ R&D investment are tax incentives. The use of this instrument is not generalized in firms spending on R&D, and only a fraction of firms are regular claimants. This paper investigates whether persistence in using tax credits is positively related to product innovations, beyond R&D investments. We consider that firms investing in qualified R&D and using tax credits regularly are likely to be firms aiming at innovating. By contrast, occasional tax credit users may be firms investing in R&D for different reasons, such as ex…
The Origins of Lactase Persistence in Europe
2009
Lactase persistence (LP) is common among people of European ancestry, but with the exception of some African, Middle Eastern and southern Asian groups, is rare or absent elsewhere in the world. Lactase gene haplotype conservation around a polymorphism strongly associated with LP in Europeans (−13,910 C/T) indicates that the derived allele is recent in origin and has been subject to strong positive selection. Furthermore, ancient DNA work has shown that the −13,910*T (derived) allele was very rare or absent in early Neolithic central Europeans. It is unlikely that LP would provide a selective advantage without a supply of fresh milk, and this has lead to a gene-culture coevolutionary model w…