Search results for "Errors"
showing 10 items of 279 documents
How do normalization schemes affect net spillovers? A replication of the Diebold and Yilmaz (2012) study
2019
Abstract This paper replicates the Diebold and Yilmaz (2012) study on the connectedness of the commodity market and three other financial markets: the stock market, the bond market, and the FX market, based on the Generalized Forecast Error Variance Decomposition, GEFVD. We show that the net spillover indices (of directional connectedness), used to assess the net contribution of one market to overall risk in the system, are sensitive to the normalization scheme applied to the GEFVD. We show that, considering data generating processes characterized by different degrees of persistence and covariance, a scalar-based normalization of the Generalized Forecast Error Variance Decomposition is pref…
Asymmetric semi-volatility spillover effects in EMU stock markets
2018
Abstract The aim of this paper is to quantify the strength and the direction of semi-volatility spillovers between five EMU stock markets over the 2000–2016 period. We use upside and downside semi-volatilities as proxies for downside risk and upside opportunities. In this way, we aim to complement the literature, which has focused mainly on the contemporaneous correlation between positive and negative returns, with the evidence of asymmetry also in semi-volatility transmission. For this purpose, we apply the Diebold and Yilmaz (2012) methodology, based on a generalized forecast error variance decomposition, to downside and upside realized semi-volatility series. While the analysis of Diebol…
HUMAN CAPITAL IN GROWTH REGRESSIONS: HOW MUCH DIFFERENCE DOES DATA QUALITY MAKE?.
2000
We construct a revised version of the Barro and Lee (1996) data set for a sample of OECD countries using previously unexploited sources and following a heuristic approach to obtain plausible time profiles for attainment levels by removing sharp breaks in the data that seem to reflect changes in classification criteria. It is then shown that these revised data perform much better than the Barro and Lee (1996) or Nehru et al (1995) series in a number of growth specifications. We interpret these results as an indication that poor data quality may be behind counterintuitive findings in the recent literature on the (lack of) relationship between educational investment and growth. Using our prefe…
Household Optimism and Borrowing
2012
A unique Finnish household-level data from 1994 to 2009 allow us to measure how households’ financial expectations are related to the subsequent outcomes. We use the difference between the two to measure forecast errors and household optimism and link the errors to households’ borrowing behaviour. We find that households making greatest optimistic forecast errors carry greater levels of debt and are most likely to suffer from excessive debt loads (overindebtedness). They also are less attentive to forecast errors than their pessimistic counterparts when forming their expectations for a subsequent period.
Intraepidermal morphologic manifestations in lysosomal diseases.
1989
This paper reports the ultrastructural findings for the epidermis of biopsied skin specimens in numerous lysosomal diseases, which can be grouped as follows: a) presence of vacuolar lysosomal residual bodies in mucopolysaccharidoses I, II and III, Salla disease, GM 2 -gangliosidoses and infantile type II glycogenosis; b) avacuolar lysosomal residual bodies in Niemann-Pick disease type C, mucolipidosis IV, Farber disease, Fabry disease, and late infantile and juvenile neuronal ceroid-lipofuscinoses; c) absence of lysosomal residual bodies in GM 2 -gangliosidoses, metachromatic leukodystrophy, Gaucher disease and sialidosis type III Whenever possible, a biopsy of the skin for morphological di…
Posterior chamber phakic intraocular lenses to improve visual outcomes in keratoconus patients
2016
The aim of this review is to summarize the results of using posterior chamber phakic intraocular lenses (pIOLs) to restore quality of vision in keratoconus patients. These pIOLs can correct the refractive errors associated with keratoconus and can also be combined with other surgical techniques to improve the results.
Two-stage adaptive designs with correlated test statistics.
2005
When performing a trial using an adaptive sequential design, it is usually assumed that the data for each stage come from different units; for example, patients. However, sometimes it is not possible to satisfy this condition or to check whether it is satisfied. In these cases, the test statistics and p-values of each stage may be dependent. In this paper we investigate the type I error of two-stage adaptive designs when the test statistics from the stages are assumed to be bivariate normal. Analytical considerations are performed under the restriction that the conditional error function is constant in the continuation region. We show that the decisions can become conservative as well as an…
The working day in medicine: lessons from the air.
2003
This article discusses whether it would be wrong to explain a mistake involving medical responsibility on the basis of an opinion that the professional was not in the optimum physical or mental state at the moment the mistake took place.
Indicators of Errors for Approximate Solutions of Differential Equations
2014
Error indicators play an important role in mesh-adaptive numerical algorithms, which currently dominate in mathematical and numerical modeling of various models in physics, chemistry, biology, economics, and other sciences. Their goal is to present a comparative measure of errors related to different parts of the computational domain, which could suggest a reasonable way of improving the finite dimensional space used to compute the approximate solution. An “ideal” error indicator must possess several properties: efficiency, computability, and universality. In other words, it must correctly reproduce the distribution of errors, be indeed computable, and be applicable to a wide set of approxi…
Una convergenza oggettiva tra mafia, terrorismo e forze eversive
2017
«Il vero nodo da sciogliere oggi è perciò quello della mafia inserita nell’attuale sistema di potere. Affrontare questo tema significa entrare nell’ordine di idee di costruire un nuovo sistema di potere, basato veramente sulla democrazia politica e sulla democrazia economica in Sicilia». Così, nel lontano 1964, e in poche sintetiche frasi, Pio La Torre offre ai deputati dell’Assemblea Regionale siciliana una lucida analisi del fenomeno mafioso; nella quale la militanza politica è indisgiungibile da una precisa idea di società e di democrazia. La mafia è un problema politico e della politica; poiché mina alla base il principio di uguaglianza e di giustizia sociale. Lo scontro con i gabelloti…