Statistical Properties of Threshold Models

This article focuses the attention on the Self Exciting Threshold Autoregressive Moving Average model (SETARMA) proposed in Tong (1983 Tong , H. ( 1983 ). Threshold Models in Nonlinear Time Series Analysis . London : Springer-Verlag .[Crossref] , [Google Scholar]). The stochastic structure of the model is discussed and different specifications are presented. Starting from one of them, we give sufficient conditions for the weak stationarity of the model that are discussed and critically compared to other results given in literature. In particular, after showing that the SETARMA model belongs to the class of the Random Coefficients Autoregressive models, widely discussed in Nicholls and Quinn (1982 Nicholls , D. F. , Quinn , B. G. (1982). Random Coefficients Autoregressive Models. An Introduction . New York : Springer-Verlag.[Crossref] , [Google Scholar]), we give some issues on the weak stationarity of its stochastic structure that are more general than those given in the existing literature and appear not affected by the moving average component.     

Low-pass filter design using locally weighted polynomial regression and discrete prolate spheroidal sequences

The paper concerns the design of nonparametric low-pass filters that have the property of reproducing a polynomial of a given degree. Two approaches are considered. The first is locally weighted polynomial regression (LWPR), which leads to linear filters depending on three parameters: the bandwidth, the order of the fitting polynomial, and the kernel. We find a remarkable linear (hyperbolic) relationship between the cut-off period (frequency) and the bandwidth, conditional on the choices of the order and the kernel, upon which we build the design of a low-pass filter.The second hinges on a generalization of the maximum concentration approach, leading to filters related to discrete prolate spheroidal sequences (DPSS). In particular, we propose a new class of low-pass filters that maximize the concentration over a specified frequency range, subject to polynomial reproducing constraints. The design of generalized DPSS filters depends on three parameters: the bandwidth, the polynomial order, and the concentration frequency. We discuss the properties of the corresponding filters in relation to the LWPR filters, and illustrate their use for the design of low-pass filters by investigating how the three parameters are related to the cut-off frequency.     

The perception of the values of urban space by senior citizens of Valparaiso

This paper is framed within the context of the Fondecyt Research Project (No. 1061179) entitled “Senior Citizens' quality of life in an Urban Habitat: Valparaiso, a Case Study.” It investigates how certain topographical conditions in the urban habitat impact on the quality of life of the population's most senior age group. Following a theoretical approach, we discuss some of the initial results obtained in our field research, integrating a quantitative technique of territorial analysis, GIS maps, and the qualitative techniques of Focus Groups and ethnographic interviews. The study of senior citizens' perceptions of their quality of life in Valparaiso indicates that the city's irregular topography and character as a heritage city mediate how the elderly perceive the urban space, creating social networks and a sense of community uniquely their own.     

The Relationship Between Social Leisure and Life Satisfaction: Causality and Policy Implications

Social leisure is generally found to be positively correlated with life satisfaction in the empirical literature. We ask if this association captures a genuine causal effect by using panel data from the GSOEP. Our identification strategy exploits the change in social leisure brought about by retirement, since the latter is an event after which the time investable in (the outside job) relational life increases. We instrument social leisure with various measures of the age cohort specific probability of retirement. With such approach we document that social leisure has a positive and significant effect on life satisfaction. Our findings shed some light on the age-happiness pattern. Policy implications are also discussed.     

Assessing the effect of the amount of financial aids to Piedmont firms using the generalized propensity score

Regional and national development policies play an important role to support local enterprises in Italy. The amount of financial aid may be a key feature for firms’ employment policies. We study the impact on employment of the amount of financial aid attributed to enterprises located in Piedmont, a region in northern Italy, analysing small-sized firms and medium- or large-sized firms separately. We apply generalized propensity score methods under the unconfoundedness assumption that adjusting for differences in a set of observed pre-treatment variables removes all biases in comparisons by different amounts of financial aid. We find that the estimated effects are increasing with amount of financial aid for both small-sized and medium- or large-sized firms, whereas the marginal effects of additional incentives are decreasing with amount of financial aid for small-sized firms, and have an inverse J-shape for medium- or large-sized firms.     

Making a (False) Impression: The Role of Business Experience in First Impressions of CEO Leadership Ability

Recent studies have demonstrated that judgments of business leaders’ faces predict their organizations’ financial performance. To date, these predictions have been derived exclusively from the impressions of naïve perceivers. Here, we tested how perceivers’ knowledge and experience in business might relate to their judgments of CEOs’ leadership ability from nonverbal facial cues. In Study 1, business students performed similarly to non-business students when rating faces for leadership ability. Business professionals with many years of experience exhibited significantly lower accuracy than professionals without business experience in Study 2, however. Following previous research demonstrating that experience in a particular domain can ironically reduce the accuracy of individuals’ judgments, our findings suggest that perceivers’ experience in executive business management positions may inhibit them from accurately judging leadership ability from nonverbal information. Domain-specific knowledge may therefore impair the accuracy of first impressions.     

Microbiological and Modeling Approach to Derive Performance Objectives for Bacillus cereus Group in Ready‐to‐Eat Salads

In this article, the performance objectives (POs) for Bacillus cereus group (BC) in celery, cheese, and spelt added as ingredients in a ready‐to‐eat mixed spelt salad, packaged under modified atmosphere, were calculated using a Bayesian approach. In order to derive the POs, BC detection and enumeration were performed in nine lots of naturally contaminated ingredients and final product. Moreover, the impact of specific production steps on the BC contamination was quantified. Finally, a sampling plan to verify the ingredient lots' compliance with each PO value at a 95% confidence level (CL) was defined. To calculate the POs, detection results as well as results above the limit of detection but below the limit of quantification (i.e., censored data) were analyzed. The most probable distribution of the censored data was determined and two‐dimensional (2D) Monte Carlo simulations were performed. The PO values were calculated to meet a food safety objective of 4 log₁₀ cfu of BC for g of spelt salad at the time of consumption. When BC grows during storage between 0.90 and 1.90 log₁₀ cfu/g, the POs for BC in celery, cheese, and spelt ranged between 1.21 log₁₀ cfu/g for celery and 2.45 log₁₀ cfu/g for spelt. This article represents the first attempt to manage the concept of PO and 2D Monte Carlo simulation in the flow chart of a complex food matrix, including raw and cooked ingredients.     

Gender-Egalitarian Attitudes and Assortative Mating by Age and Education

European Journal of Population - In the last decades, conventional patterns of assortative mating have been challenged by changes in the gender-gap in education. In many countries, educationally...