Loud callings limit human tolerance towards invasive parakeets in urban areas

Biological invasions represent today one of the main cause of the global biodiversity crisis, particularly in urban and suburban areas. Research on this topic have traditionally focused on ecological impacts, with poor regards to the social components. The ring-necked parakeet Psittacula krameri is one of the most successful invaders and it is widely appreciated by the general public, being introduced through the pet trade. In this work we assessed whether long-term introduction, total population size and number of loud flight-calls affected social perception of this species in three populations from Italian cities. We used a visual survey (N?=?414 questionnaires), which has been proven to be successful for testing attitudes on ring-necked parakeets. Tolerance towards this invasive species declined sharply with increasing number of loud calls by this species, thus providing support to the hypothesis of involvement of the ring-necked parakeet in noise pollution. Conversely, total population size and years since the first local introduction were not found out to be important variable determining social attitudes. Awareness on invasive species impacts is mostly obtained only when invasive populations are already affecting native biodiversity and human wellness, thus when management becomes challenging. Thus, at early invasion stages, intervention towards invasive species, particularly if charismatic, are often hampered by social public and animal right movements, especially in urban ecosystems. Educational campaigns on ecological and social impact by invasive alien species in urban ecosystems are therefore strongly recommended to implement effective management actions.

     

Testing for cointegration at any frequency using spectral methods

Summary In this paper a new simple test for cointegration at any frequency is presented. This method can thus be applied to test for cointegration both at the zero and at the seasonal frequencies. It requires the estimation of the coherency spectrum of weakly stationary processes, therefore only standard spectral theory is involved. The testing procedure is similar to the one suggested by Phillips and Ouliaris (1988) and recently generalized by Joyeux (1992) to frequencies different from zero, but it does not suffer of some problems connected with the use of principal components methods in the frequency domain. Invited paper at the Conference held in Bologna, Italy, 27–28 May 1993, on ?Statistical Tests: Methodology and Econometric Applications?.     

Long-term Growth Perspectives and Economic Convergence of CEE and SEE Countries

The paper first investigates the main drivers of economic growth and real convergence in CEE and SEE Countries. In the theoretical framework provided by the growth-accounting approach, both are shown to be driven by capital accumulation and total factor productivity changes, with the latter making however a major contribution. The nominal convergence path towards the Eurozone is then analysed. Despite considerable results obtained in the last decade, most EU new members are still found to face severe challenges in the process of converging towards Maastricht criteria. The need to reconcile exchange rate stability with inflation convergence is in particular seen to be at the heart of their de facto decision to delay the EMU entry date until a higher degree of real convergence will have been achieved.

Semiautomatic robust regression clustering of international trade data

The purpose of this paper is to show in regression clustering how to choose the most relevant solutions, analyze their stability, and provide information about best combinations of optimal number of groups, restriction factor among the error variance across groups and level of trimming. The procedure is based on two steps. First we generalize the information criteria of constrained robust multivariate clustering to the case of clustering weighted models. Differently from the traditional approaches which are based on the choice of the best solution found minimizing an information criterion (i.e. BIC), we concentrate our attention on the so called optimal stable solutions. In the second step, using the monitoring approach, we select the best value of the trimming factor. Finally, we validate the solution using a confirmatory forward search approach. A motivating example based on a novel dataset concerning the European Union trade of face masks shows the limitations of the current existing procedures. The suggested approach is initially applied to a set of well known datasets in the literature of robust regression clustering. Then, we focus our attention on a set of international trade datasets and we provide a novel informative way of updating the subset in the random start approach. The Supplementary material, in the spirit of the Special Issue, deepens the analysis of trade data and compares the suggested approach with the existing ones available in the literature.

     

Italian Adult Gambling Behavior: At Risk and Problem Gambler Profiles

The present study examined adult gambling behaviours from a local perspective in order to assess the adult at risk and problem gambler’s profile stratified by genre and by different forms of game. 4773 Italian adults from 18 to 94 years old were administered a survey to assess socio-cultural information related to gambling behaviour and the SOGS to evaluate gambling behaviour severity. Logistic regression evidenced that both at risk and problem gamblers are associated with male gender, players that use to play to more than one game, gambling with strategy-based games. People with a gambler father or both parents who used to gamble were significantly more associated with problem gambling behaviour than participants with non-gambler parents. These results present adult profiles of at risk and problem providing a more clear understanding about the relationships between gambling behavior severity and type of gambling.     

Improving innovation performance through environmental practices in the fashion industry: the moderating effect of internationalisation and the influence of collaboration

In recent years, the scientific literature on supply chain management has increasingly debated on environmental sustainability as well as collaboration, presenting these issues as an important source of innovation along the supply chain. By combining literature streams on environmental sustainability, supply chain collaboration and innovation at the supply chain level, this paper aims to analyse whether the adoption of environmental sustainability practices and collaboration along the supply chain implies better innovation performance, in terms of differentiation from the competitors for higher quality, product or process. The paper also investigates whether the internationalisation, in terms of both production and distribution activities, negatively moderates this relationship. The study focuses on the fashion industry, and a survey of major Italian fashion companies was conducted. The main results of the research clearly show the positive impact of these practices on innovation performance. The paper also proves the existence of a moderating effect exerted by internationalisation on the relationship between environmental sustainability and innovation performance.     

Micro-simulation of households: a new tool to assess the impact on society of food safety policies

Public concerns about the risk from food hazards have spread in recent years, boosted by a number of well-publicized food scares. As a result, food safety issues are high on the policy agenda in Europe and elsewhere, and a range of policies have been developed to deal with them. The paper illustrates and makes a case for the use of micro-simulation models as support for better economic assessment of food policies. When households deal with food safety issues they can show heterogeneous behaviors, and micro-simulation can provide a useful tool to take into account this heterogeneity. However, to the author's knowledge, no attempt to use micro-simulation in the analysis of food safety policies has taken place so far. After an illustration of the way economists evaluate food safety policies, micro-simulation methodologies are introduced, stressing their potentiality for the assessment of food safety policies.     

Becoming the best: by beating or ignoring the best? Toward an expanded view of the role of managerial selection in complex and turbulent environments

This paper explores how the rules that guide search affect organizational adaptation in complex and turbulent environments. Our consideration of such rules extends beyond search scope—i.e., exploitation of current technologies vs. exploration of new technologies—to include focus on competition. We consider two types of competitive focus—i.e., external, where the choice of focal technology to be improved is influenced by information about other organizations and internal, where it is not influenced by others. We refer to this expanded set of rules as managerial selection and vary it to explore how it affects organizational adaptation. Employing an agent based simulation model, built on the framework of NKC fitness landscapes, we consider multiple types of interdependencies within and between technologies and across competitors. We show that in the presence of these multiple interdependencies, the ability of organizations to adapt is conditioned as much or more by the focus of search than by its scope. In particular, we observe that in simple and stable environments, organizational adaptation is enhanced by an external focus but in complex and turbulent environments, such external focus is counterproductive.     

Anonymizing binary and small tables is hard to approximate

The problem of publishing personal data without giving up privacy is becoming increasingly important. An interesting formalization recently proposed is the k-anonymity. This approach requires that the rows in a table are clustered in sets of size at least k and that all the rows in a cluster become the same tuple, after the suppression of some records. The natural optimization problem, where the goal is to minimize the number of suppressed entries, is known to be NP-hard when the values are over a ternary alphabet, k=3 and the rows length is unbounded. In this paper we give a lower bound on the approximation factor that any polynomial-time algorithm can achieve on two restrictions of the problem, namely (i) when the records values are over a binary alphabet and k=3, and (ii) when the records have length at most 8 and k=4, showing that these restrictions of the problem are APX-hard.