Search results for "Econometric"
showing 10 items of 3780 documents
Introduzione al numero monografico sulla Comunicazione istituzionale
2015
Questo numero di Rivista Trimestrale di Scienze dell’Amministrazione (RTSA) raccoglie contributi di vari studiosi e professionisti al tema della comunicazione istituzionale. Gli articoli sono il frutto di una serie di relazioni tenute in occasione dei seminari delle Classi di Laurea in Scienze della Comunicazione dell’Università degli Studi di Palermo svolti nei mesi di maggio e giugno 2015. I seminari sono stati organizzati dall’associazione studentesca Unione degli Universitari (UDU) su iniziativa di Fabio Massimo Piazza, dottore magistrale in Scienze della Comunicazione pubblica, sociale e istituzionale. L’idea è stata quella di offrire al pubblico degli studenti dell’Ateneo di Palermo e…
I costi dell'azione amministrativa per i cittadini e le imprese
2015
Scopo di questo studio è comprendere i costi delle complicazioni burocratiche per i cittadini e le imprese e in che modo essi possono essere ridotti e tenuti sotto controllo. L’articolo affronta pertanto i seguenti temi. Il concetto di complicazione burocratica così come si è sviluppato nella letteratura di riferimento e le relazioni che intercorrono con i costi dell’azione amministrativa. Le politiche dei governi nazionali intraprese per contrastare i costi della burocrazia. La metodologia di stima e misurazione dei costi dell’azione amministrativa - lo Standard Cost Model - diffusasi e consolidatasi nel contesto europeo. Le misure di semplificazione per la riduzione dei costi degli oneri …
Prioritisation of alternatives with analytical hierarchy process plus response latency and web surveys
2014
This paper introduces a new method that combines the well-known analytical hierarchy process (AHP) with a response latency metric. The response latency is the time taken by respondents to make choices over pairwise comparisons. The analytical calculation of relative importance weights of the alternatives is made by using a response latency model previously validated in several case studies. This combination aims to overcome some drawbacks of the traditional AHP related to the use of a rating scale (the so-called Saaty scale), and it is a natural way to involve response latency in established decisionmaking methods. This new method can be profitably adopted in web surveys where it is easy to…
Geographical Distribution of Crime: A Spatial Econometric Analysis
2007
Since long time social sciences have focused their attention on the causes of crime activities and this attention evolved over time. The sociological school emphasised the role of neighbourhood in delinquency activities, their stability over time and the existence of a negative relation between crimes and business centres (Shaw and McKay, 1942). This perspective stimulated the analysis of the existing nexus between crime activities and their geographical proximity. The economics approach moved differently. Since late 60s the economic analyses devoted their attention to the detection of mechanisms affecting the choice and behaviour of criminals (Becker, 1968; Stigler, 1970; Ehrlich, 1973). B…
Discrete Time Portfolio Selection with Lévy Processes
2007
This paper analyzes discrete time portfolio selection models with Lévy processes. We first implement portfolio models under the hypotheses the vector of log-returns follow or a multivariate Variance Gamma model or a Multivariate Normal Inverse Gaussian model or a Brownian Motion. In particular, we propose an ex-ante and an ex-post empirical comparisons by the point of view of different investors. Thus, we compare portfolio strategies considering different term structure scenarios and different distributional assumptions when unlimited short sales are allowed.
Another Look on Choosing Factors: The International Evidence
2019
Extending Fama and French’s (2018) U.S. study on choosing factors to international equity markets, we test nested and non-nested asset pricing models for North America, Europe, Asia excluding Japan, and Japan. For non-nested models, we propose a new simulation methodology using a blocks bootstrap approach that takes into account factor dependencies. The resultant out-of-sample Sharpe ratios across all models and countries are lower than Fama and French’s pairs bootstrap approach. While we confirm that the six-factor model with market, size, and small size spread factors for value, profit, investment, and momentum produces the highest maximum squared Sharpe ratio in most economies, an except…
Weighted-Average Least Squares (WALS): Confidence and Prediction Intervals
2022
We extend the results of De Luca et al. (2021) to inference for linear regression models based on weighted-average least squares (WALS), a frequentist model averaging approach with a Bayesian flavor. We concentrate on inference about a single focus parameter, interpreted as the causal effect of a policy or intervention, in the presence of a potentially large number of auxiliary parameters representing the nuisance component of the model. In our Monte Carlo simulations we compare the performance of WALS with that of several competing estimators, including the unrestricted least-squares estimator (with all auxiliary regressors) and the restricted least-squares estimator (with no auxiliary reg…
A proof of bistability for the dual futile cycle
2014
Abstract The multiple futile cycle is an important building block in networks of chemical reactions arising in molecular biology. A typical process which it describes is the addition of n phosphate groups to a protein. It can be modelled by a system of ordinary differential equations depending on parameters. The special case n = 2 is called the dual futile cycle. The main result of this paper is a proof that there are parameter values for which the system of ODE describing the dual futile cycle has two distinct stable stationary solutions. The proof is based on bifurcation theory and geometric singular perturbation theory. An important entity built of three coupled multiple futile cycles is…
Skewness in individual stocks at different investment horizons
2002
Abstract This paper examines the (a)symmetry of several individual stock returns at different investment horizons: daily, weekly and monthly. While some asymmetries are observed in daily returns, they disappear almost completely in weekly and monthly returns. The explanation for this fact lies in the convergence to normality that takes place when the investment horizon increases. These features allow one to question several financial models; in particular, they question the preference for positive skewness as a factor for investments in stock markets.
A Generalisation of the Mean-Variance Analysis
2009
In this paper we consider a decision maker whose utility function has a kink at the reference point with different functions below and above this reference point. We also suppose that the decision maker generally distorts the objective probabilities. First we show that the expected utility function of this decision maker can be approximated by a function of mean and partial moments of distribution. This ‘mean-partial moments’ utility generalises not only mean-variance utility of Tobin and Markowitz, but also mean-semivariance utility of Markowitz. Then, in the spirit of Arrow and Pratt, we derive an expression for a risk premium when risk is small. Our analysis shows that a decision maker i…