Sandra García-Bustos, Nadia Cárdenas-Escobar, Ana Debón and César Pincay
The study aims to design a control chart based on an exponentially weighted moving average (EWMA) chart of Pearson's residuals of a model of negative binomial regression in order…
Abstract
Purpose
The study aims to design a control chart based on an exponentially weighted moving average (EWMA) chart of Pearson's residuals of a model of negative binomial regression in order to detect possible anomalies in mortality data.
Design/methodology/approach
In order to evaluate the performance of the proposed chart, the authors have considered official historical records of death of children of Ecuador. A negative binomial regression model was fitted to the data, and a chart of the Pearson residuals was designed. The parameters of the chart were obtained by simulation, as well as the performances of the charts related to changes in the mean of death.
Findings
When the chart was plotted, outliers were detected in the deaths of children in the years 1990–1995, 2001–2006, 2013–2015, which could show that there are underreporting or an excessive growth in mortality. In the analysis of performances, the value of λ = 0.05 presented the fastest detection of changes in the mean death.
Originality/value
The proposed charts present better performances in relation to EWMA charts for deviance residuals, with a remarkable advantage of the Pearson residuals, which are much easier to interpret and calculate. Finally, the authors would like to point out that although this paper only applies control charts to Ecuadorian infant mortality, the methodology can be used to calculate mortality in any geographical area or to detect outbreaks of infectious diseases.
Details
Keywords
Desamparados Blazquez, Josep Domenech and Ana Debón
The purpose of this paper is to analyze to what extent changes in corporate websites reflect firms’ survival. Since keeping a website online involves some costs, it is likely that…
Abstract
Purpose
The purpose of this paper is to analyze to what extent changes in corporate websites reflect firms’ survival. Since keeping a website online involves some costs, it is likely that firms would invest resources on it only when they are active and healthy. Therefore, when a firm dies, this event is likely to be manifested on its website as lacking updates or being down.
Design/methodology/approach
Changes in the corporate websites of a panel of Spanish firms were tracked between 2008 and 2014 in order to evaluate the approach. The status of websites, classified according to the type of change undergone, was used to infer firms’ activity status (active or inactive). Multi-period logistic regressions and a duration model were applied to study the relationship among the website status and the firm’s status.
Findings
Results showed that changes in website contents clearly reflect the firm’s status. Active firms were mainly associated with updated corporate websites, while inactive firms were more associated with down websites. In fact, results confirmed that the firms’ death hazard increases when the website activity lowers.
Originality/value
Although online information is increasingly being used to monitor the economy, this is the first study to connect online data to firms’ survival. The results revealed a new source of information about business demography and evidenced corporate websites as a fresh source of high granularity business data.
Details
Keywords
It is possible to say that an expert in any field of knowledge can be expected to know particular things and techniques. This can be said of a stone mason, a physicist or a…
Abstract
It is possible to say that an expert in any field of knowledge can be expected to know particular things and techniques. This can be said of a stone mason, a physicist or a midwife. The expertise consists of a notional core of knowledge and skills (i.e. applied knowledge). Such expertise arguably can be found in other experts in the same field, although there will be idiosyncrasies of approach and valuation and quite probably divergencies in what is considered “right” and “wrong”.
The broader context in the last twenty years awareness of the information and documentation problems of the social sciences has grown, but almost as if by stealth. During that…
Abstract
The broader context in the last twenty years awareness of the information and documentation problems of the social sciences has grown, but almost as if by stealth. During that period there have been significant developments for practice, organization and research in social science information, but knowledge of these has remained largely confined to small groups of specialists closely associated with them. In the main it has been library and information developments in science and technology that have captured the interest and attention of the majority of professionals and specialists as such: for example, the development of computer‐based citation indexes; the introduction of the computer database as a successor to the printed secondary journal; the development of online search facilities and associated software and retrieval techniques; the exploitation of telecommunications and computers to create new information technology, leading to alternative means of interpersonal communication, the possibilities of electronic journals and a vision of the paperless society. This situation is hardly surprising since science and technology provide the productive base for advanced societies.
As libraries and information centers grow in complexity and, in many cases, become big business, financial management skills take on increased importance for librarians and other…
Abstract
As libraries and information centers grow in complexity and, in many cases, become big business, financial management skills take on increased importance for librarians and other information workers. External and internal pressures like reductions in library budgets, escalation of costs faster than revenues, pressures from outside agencies for increased productivity, accountability, organizational efficiency and effectiveness have all pushed librarians to expand their competencies in the financial arena.
One difficulty faced by students on many information management courses is the lack of any attempt to teach concepts of information. Therefore, if a core module does not fit in…
Abstract
One difficulty faced by students on many information management courses is the lack of any attempt to teach concepts of information. Therefore, if a core module does not fit in with a student’s existing concept of information, it can make it hard for the student to recognise the relevance of that module. This paper addresses that problem by summarising concepts of information, and by presenting a simple model that attempts to unite the various concepts listed. The model is based on the idea that the meaning in a message depends on the context in which the message originated (the authorial context), and the context in which it is interpreted (the readership context). Characteristics of authors, readers and messages are discussed. The impact of the ‘knowledge’ of ‘information’ users, and of their community, is considered. Implications of the model are discussed. A definition of information is suggested, which attempts to encapsulate the nature of information implied by the model.