Generalized value at risk forecasting

Abstract

In this paper, using estimating function approach, a new optimal volatility estimator is introduced and based on the recursive form of the estimator a data-driven generalized EWMA model for value at risk (VaR) forecast is proposed. An appropriate data-driven model for volatility is identified by the relationship between absolute deviation and standard deviation for symmetric distributions with finite variance. It is shown that the asymptotic variance of the proposed volatility estimator is smaller than that of conventional estimators and is more appropriate for financial data with larger kurtosis. For IBM, Microsoft, Apple stocks and SP 500 index the proposed method is used to identify the model, estimate the volatility, and obtain minimum mean square error(MMSE) forecasts of VaR.     

Tablet assessment of word comprehension reveals coarse word representations in 18–⁠20-month-old toddlers

The present study explores the viability of using tablets in assessing early word comprehension by means of a two-alternative forced-choice task. Forty-nine 18–20-month-old Norwegian toddlers performed a touch-based word recognition task, in which they were prompted to identify the labeled target out of two displayed items on a touchscreen tablet. In each trial, the distractor item was either semantically related (e.g., dog–cat) or unrelated (e.g., dog–airplane) to the target. Our results show that toddlers as young as 18 months can engage meaningfully with a tablet-based assessment, with minimal verbal instruction and child–administrator interaction. Toddlers performed better in the semantically unrelated condition than in the related condition, suggesting that their word representations are still semantically coarse at this age. Furthermore, parental reports of comprehension, using the Norwegian version of the MacArthur–Bates Communicative Development Inventories, predicted toddlers’ performance, with parent–child agreement stronger in the semantically unrelated condition, indicating that parents declare a word to be known by their child if it is understood at a coarse representational level. This study provides among the earliest evidence that remote data collection in 18-20 month-old toddlers is viable, as comparable results were observed from both in-laboratory and online administration of the touchscreen recognition task.     

Justice as social representation: diffusion and differential positioning / La justicia como representación social: difusión y posicionamientos diferenciales

The aim of this paper is to analyse the relationship between the diffusion process of social representations of justice by the press and their appropriation by readers. Two simultaneous cross-sectional studies were carried out. Study 1 analysed the meaning and the frequency of the word justice in the most important newspaper in Buenos Aires. The results indicate that the representation of justice has a retributive and institutional meaning. Study 2 investigated university students’ social representations of justice (N = 404) through a word association technique. The results showed that the central core of social representation has a retributive and institutional meaning, similar to the representations diffused by the most important newspaper. Nevertheless, significant differences were found with regard to the value attached to justice depending on the newspaper that the participants claimed to read. We can conclude that there is a mutual constitutive circular movement between the social representation of justice diffused by the newspapers and university students’ social representations. Moreover, the differences identified in the way justice was evaluated in the peripheral elements might express the existence of different positionings related to a hegemonic social representation.     

WHO QUITS NEXT? FIRM GROWTH IN GROWING ECONOMIES

We document novel facts about the relationship between aggregate growth and firm dynamics using a large set of countries. We argue that firm employment patterns are not necessarily informative about cross‐country differences in aggregate growth because they are induced by changes in the productivity of a firm relative to others. In contrast, aggregate growth is linked to average firm‐level productivity growth and firm age. We formalize this intuition through a tractable model of endogenous aggregate growth and firm dynamics where firms realize positive returns to investment with some probability. We find that cross‐country disparities in this probability can account for two‐thirds of the variation in aggregate growth. (JEL D21, D22, E23, O4)     

Social Work Education in the Urban Scene

This paper describes one possible approach of integrating the key areas of racism and sexism into the human behavior sequence. It is suggested that power relations among people has become a unifying concept of human behavior in modern society, replacing the Freudian libido. Under this conceptual umbrella the relationship between men and women, between races, between social classes, and between helping professionals and their clients can all be examined. General principles of human behavior, such as aggression theories, childhood socialization, defense mechanisms, role theory, verbal and nonverbal communication, and other themes can be introduced to support the basic framework.