STATISTICA & APPLICAZIONI - 2021 - 2

In social psychology, reputation has been studied with reference to different objects (individuals, brands, cities, etc.) and methodologically, measured discerning between its subdimensions. In this article, city reputation is  operationally defined, by using the validated City Reputation Indicators scale. This empirical tool is useful to evaluate the separate dimensions of city reputation independently. Data, obtained from a survey administered in the city of  Naples, were analysed using the Classification-tree, a non-parametric procedure, widely used in supervised classification. We also used the Spearman rank correlation, in order to assess the degree of association between overall  citizen satisfaction and overall city reputation. The classification tree has made possible the identification of the key path which better identifies people considering Naples a city with a good reputation. Furthermore, results also show the main constituents of city reputation.

Vector autoregressive (VAR) model is the most popular modeling tool in macroeconomics. This study considers a Bayesian framework for VAR(k) model with a structural break in the mean. The structural change problem in VAR is of  theoretical and practical importance in reference to the economic time series data. The main motivation of the study is to identify the impact of the break in the series and estimate the model parameters in the presence of the break  considering appropriate prior assumptions. A simulation study and empirical analysis of the net asset value of national pension schemes for different fund managers have been carried out to justify the proposed mechanism.

The financial literature proposed many contributions to measure the credit risk, in this work a survival approach is proposed to reach this purpose. Having available the survival times for each credit line, the choice was oriented to  survival models to evaluate the pathological death of the loan. A survival analysis was conducted on a dataset containing 5322 credits for Italian companies through a Cox model considering some risk factors about both the company  and the loan. The selected Cox model led to the identification of risk profiles representing different situations in terms of probability of insolvency.

The most common method for studying historical data is to use regression methods and predictive modeling on time series data. The parametric methodology for time series data analysis is a customary method when the data are  available on a continuous scale. However, most of the time, the data availability may be on a categorical or ordinal scale. Hence, the nonparametric methodology is more rational in handling time series data. This study considers two  prominent non-parametric methods, namely Pettitt’s test and Buishand’s range test. In particular, we examine an abrupt change in the annual data of rice production during the period 1980-2020 by these methods. The study  continued to assess the performance of rice production with the presence and absence of trend as performed by the Mann-Kendall test and the trend measured by Sen’s slope estimator. According to the findings, the second time period’s average growth rate has improved slightly but not as significantly as the first time period’s.