Balanced sampling of boxes from batches for assessing quality of fruits and vegetables in EU countries

Quality & Quantity - The best evaluation for the proportion of defective units in a batch of fruits and vegetables can be achieved by an exhaustive checking of all the boxes in the batch, that...     

The Role of Foreign Shareholders in Disciplining Financial Reporting

We investigate the role of foreign shareholders in improving the quality of accounting information provided by firms domiciled in countries with low de facto institutional quality. Using a sample of firms from four South European countries (Greece, Italy, Portugal and Spain) for which we observe detailed ownership evolutions over the period 2002–2007, we find that increases in foreign ownership lead to increases in financial reporting quality but only if the foreign shareholders are domiciled in countries with strong investor protection mechanisms. Further, we find that the improvement in financial reporting quality is more pronounced in the case of foreign institutional investors. Finally, our results hold before and after the introduction of the International Financial Reporting Standards (IFRS) in 2005.     

Unobserved Heterogeneity,Exit Rates,and Re‐Employment Wages

Exit rates from unemployment and re‐employment wages decline over a period of unemployment, after controlling for worker observable characteristics. We study the role of unobserved heterogeneity in an economy with asymmetric information and directed search. We show that the unique equilibrium is separating and that skilled workers have more job opportunities and higher wages. The composition of the unemployed varies with the duration of unemployment, so average exit rates and wages fall with time. The separating equilibrium relies on performance‐related pay schemes and the ability of firms to commit to renting an input that is complementary to worker skills.     

Inference on factor structures in heterogeneous panels

This paper develops an estimation and testing framework for a stationary large panel model with observable regressors and unobservable common factors. We allow for slope heterogeneity and for correlation between the common factors and the regressors. We propose a two stage estimation procedure for the unobservable common factors and their loadings, based on Common Correlated Effects estimator and the Principal Component estimator. We also develop two tests for the null of no factor structure: one for the null that loadings are cross sectionally homogeneous, and one for the null that common factors are homogeneous over time. Our tests are based on using extremes of the estimated loadings and common factors. The test statistics have an asymptotic Gumbel distribution under the null, and have power versus alternatives where only one loading or common factor differs from the others. Monte Carlo evidence shows that the tests have the correct size and good power.     

The relation between segment disclosure and earnings quality

We investigate the relation between segment disclosure and earnings quality. Using a US sample for the period 2001–2006, we find a positive relation between earnings quality and the quantity of segment disclosures. We use lead-lag tests to examine the flow of causality, and our results show that current segment disclosure is positively related to prior levels of earnings quality, while current earnings quality scores are not related to prior levels of segment disclosure. Thus, the causality flows from earnings quality to segment disclosure. Our results hold for both business and geographic segment disclosure.     

Reducing the mean supply delay of spare parts using lateral transshipments policies

Lateral transshipment has been studied lately as a promising policy for increasing the performances of multi-echelon spare parts inventory system. By lateral transshipment spare parts can be moved from one location with excess inventory to another location, at the same echelon, in shortage, with the aim of reducing supply delays of spare parts. This paper will examine the relative effectiveness of two lateral shipments approaches in reducing the mean supply delay (MSD) of a non-repairable item, with respect to a classical policy of no lateral shipments. A simulation model of a two echelon supply network has been implemented and an experiment has been performed by varying different parameters of the supply network, such as the number of warehouses (locations at the lower echelon), the supply lead time from the central depot, the spare parts demand uncertainty, and the size variability of the warehouses. Results show appreciable reductions of MSD when lateral shipments are allowed with respect to the classical policy, in almost every network configuration.     

Destination Online Communication: Why Less is Sometimes More. A Study of Online Communications of English Destinations

This research investigates the relationship between Web site design and the Web site end-user experience of a vast number of English tourism destinations, both local and regional ones. Following recent research in the field, this paper evaluates destinations’ online communication based on the implemented Web site features and on the effectiveness of the communication itself, borrowing its research methodology from different domains. After content and functionality analysis, a user-experience, scenario-based investigation has been carried out, which demonstrated that complex Web sites do not always serve end-users’ needs properly; in other words, Web site complexity is not directly related with good user experience. This research may help destination managers to foster their online communication if they have fewer content and functionalities but are better focused and clearly user-oriented.     

Equilibrium with endogenous technological changes: Theory and applications

In this paper we use a continuous-time general equilibrium model to analyze the problem of evaluating new irreversible investment opportunities that take the form of technological changes. Being a new technology, by definition, not perfectly correlated with the existing ones, the traditional spanning assumption invoked by the Real Option literature is not applicable in this context and a general equilibrium approach provides a more suitable framework. We analyze the problem of optimal consumption and investment of the representative individual in the context of the Cox Ingersoll and Ross (1895) model. We characterize the solution of the model under different assumptions about the utility function of the representative individual and about the parameters describing the technologies in the economy. A major result obtained from the model is the possibility of jumps in the equilibrium rate of return at the time in which technological changes are implemented. This is particularly interesting considering the fact that such jumps are obtained endogenously from the solution of the optimization problem and not imposed by “ad hoc” assumptions on the evolution of some variables.

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Riassunto Un modello di equilibrio economico generale in tempo continuo è utilizzato per analizzare il problema di valutare una nuova, irreversibile, opportunità di investimento che si presenta sotto forma di innovazione tecnologica. Essendo, per definizione, la nuova tecnologia non perfettamente correlata con le tecnologie esistenti, la letteratura delle “opzioni reali” non è applicabile ed un modello di equilibrio economico generale fornisce un ambiente più adatto allo studio del problema. Facendo uso del modello di Cox Ingersoll and Ross (1985) si fornisce una soluzione sotto diverse ipotesi riguardanti la struttura delle preferenze e la natura dell'innovazione tecnologica. Un interessante risultato è la derivazione di possibili discontinuità nel tasso di interesse di equilibrio in corrispondenza dell'adozione della nuova tecnologia.

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I would like to express my gratitude to Vasant Naik, David Peterson, Raman Uppal and especially Burton Hollifield and Tan Wang for helpful discussions and suggestions.     

Bootstrapping Financial Time Series

It is well known that time series of returns are characterized by volatility clustering and excess kurtosis. Therefore, when modelling the dynamic behavior of returns, inference and prediction methods, based on independent and/or Gaussian observations may be inadequate. As bootstrap methods are not, in general, based on any particular assumption on the distribution of the data, they are well suited for the analysis of returns. This paper reviews the application of bootstrap procedures for inference and prediction of financial time series. In relation to inference, bootstrap techniques have been applied to obtain the sample distribution of statistics for testing, for example, autoregressive dynamics in the conditional mean and variance, unit roots in the mean, fractional integration in volatility and the predictive ability of technical trading rules. On the other hand, bootstrap procedures have been used to estimate the distribution of returns which is of interest, for example, for Value at Risk (VaR) models or for prediction purposes. Although the application of bootstrap techniques to the empirical analysis of financial time series is very broad, there are few analytical results on the statistical properties of these techniques when applied to heteroscedastic time series. Furthermore, there are quite a few papers where the bootstrap procedures used are not adequate.     

Funding a PAYG pension system: the case of Italy

Italy is characterised by a mature pay‐as‐you‐go social security system and by particularly adverse population projections. Given these trends, the social security contribution rate is expected to increase above its current high level. This hinders the development of employer‐provided pension funds and introduces a significant wedge between labour cost and earnings that discourages both labour demand and labour supply. Any proposal to reduce payroll taxes and to reform the system in the direction of partial funding has to cope with the state of Italian public finances. Italy has to comply with the Stability and Growth Pact that imposes constraints on budget deficit and debt trends. Using micro data from the Bank of Italy's Survey of Household Income and Wealth and official population projections, we estimate future employment trends under different demographic and macroeconomic scenarios and compute the cost of the transition. We show that it would be substantially reduced if positive effects on employment were induced by the payroll tax reduction.