On bootstrapping panel factor series

This paper studies the asymptotic validity of sieve bootstrap for nonstationary panel factor series. Two main results are shown. Firstly, a bootstrap Invariance Principle is derived pointwise in i$i$, obtaining an upper bound for the order of truncation of the AR polynomial that depends on n$n$ and T$T$. Consistent estimation of the long run variances is also studied for (n,T)→∞$(n,T)\to \infty$. Secondly, joint bootstrap asymptotics is also studied, investigating the conditions under which the bootstrap is valid. In particular, the extent of cross sectional dependence which can be allowed for is investigated. Whilst we show that, for general forms of cross dependence, consistent estimation of the long run variance (and therefore validity of the bootstrap) is fraught with difficulties, however we show that “one-cross-sectional-unit-at-a-time” resampling schemes yield valid bootstrap based inference under weak forms of cross-sectional dependence.     

Optimal forecasting with heterogeneous panels: A Monte Carlo study

We contrast the forecasting performance of alternative panel estimators, divided into three main groups: homogeneous, heterogeneous and shrinkage/Bayesian. Via a series of Monte Carlo simulations, the comparison is performed using different levels of heterogeneity and cross sectional dependence, alternative panel structures in terms of T and N and the specification of the dynamics of the error term. To assess the predictive performance, we use traditional measures of forecast accuracy (Theil’s U statistics, RMSE and MAE), the Diebold–Mariano test, and Pesaran and Timmerman’s statistic on the capability of forecasting turning points. The main finding of our analysis is that when the level of heterogeneity is high, shrinkage/Bayesian estimators are preferred, whilst when there is low or mild heterogeneity, homogeneous estimators have the best forecast accuracy.     

An evaluation of the performance and suitability of R × C methods for ecological inference with known true values

Ecological inference refers to the study of individuals using aggregate data and it is used in an impressive number of studies; it is well known, however, that the study of individuals using group data suffers from an ecological fallacy problem (Robinson in Am Sociol Rev 15:351–357, 1950). This paper evaluates the accuracy of two recent methods, the Rosen et al. (Stat Neerl 55:134–156, 2001) and the Greiner and Quinn (J R Stat Soc Ser A (Statistics in Society) 172:67–81, 2009) and the long-standing Goodman’s (Am Sociol Rev 18:663–664, 1953; Am J Sociol 64:610–625, 1959) method designed to estimate all cells of R × C tables simultaneously by employing exclusively aggregate data. To conduct these tests we leverage on extensive electoral data for which the true quantities of interest are known. In particular, we focus on examining the extent to which the confidence intervals provided by the three methods contain the true values. The paper also provides important guidelines regarding the appropriate contexts for employing these models.     

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.     

An Open Innovation Decision Support System to Select a Biopharmaceutical R&D Portfolio

Drugs available in the market today, selected several years ago under very uncertain future scenario, have experienced a long and expensive process of research and development carried out following both a closed and an open innovation path. To support this critical selection process, we propose a Decision Support System, able to choose among different candidates the most promising drugs along their best development path. The Decision Support System, based on a real options portfolio optimization model, mapping tools, and what‐if rules as well, has been applied to a numerical example available in literature, and the research findings show interesting managerial and academic implications. Copyright © 2015 John Wiley & Sons, Ltd.     

The relationship between Entrepreneurial Orientation,Market Orientation and Performance in University Spin-Offs

The paper aims to examine the relationship between Entrepreneurial Orientation (EO), Market Orientation (MO) and performance in University Spin-Offs (USOs). Initially, the paper, assesses the existence of a moderating effect of MO in the relationship between EO and performance, next, it analyses the mediation role of MO between EO and performance. To strengthen paper results, we test our hypotheses on a cross-sectional sample of 162 Italian USOs using both perceived and objective performance. Findings suggest that there is no synergistic effect of MO and EO as mutually independent constructs. Instead, our evidences support the idea that EO and MO in USOs occur within the same learning process. Both EO and MO support USO performance, but MO cannot occur without EO as an antecedent condition. At the same time, a significant portion of the EO contribution to performance occurs through MO.

     

Strategic accessibility competition

We analyze the effect of competition in market-accessibility enhancement among quality-differentiated firms. Firms are located in regions with different ex-ante transport costs to reach the final market. We characterize the equilibrium of the two-stage game in which firms first invest to improve market accessibility and then compete in prices. Efforts in accessibility improvement crucially depend on the interplay between the willingness to pay for the quality premium of the median consumer and the ex-ante difference in accessibility between regions. From the social standpoint, also the accessibility investment depends on such a comparison. Finally, we endogenize quality choice and check the robustness of the result to some natural modifications of our assumptions.     

Family ownership and environmental performance: The mediation effect of human resource practices

Previous literature has found that listed family firms underperform their nonfamily counterparts in terms of environmental performance, but has not explained why this occurs. We address this research gap by hypothesizing that training and development practices (i.e., managerial practices devoted to providing training and development for the workforce) mediate the relationship between family blockholders and environmental performance. Using a sample of 33,901 firm‐year observations from 2002 to 2016 distributed across 56 countries and employing the structural equation model technique, we find that investment in training and development practices explains almost half of the negative relationship between family blockholders and environmental performance. Our study contributes to the agency theory debate on principal–principal problems by explaining why family blockholders could damage other blockholders and minority shareholders.     

Why should black-owned businesses hire predominately black labor forces?

In the past, black-owned businesses appear to have hired a predominately black labor force. This article questions if incentives exist for them to continue to do so in the future. Various discrimination incentives are discussed and largely dismissed. It is concluded that the qualifications for gaining access to set-aside contracts and subsidies do provide incentives for black-owned businesses to hire a predominately black labor force.     

A note on symmetry breaking in a non linear marketing model

Decisions in Economics and Finance - In this paper, we consider the nonlinear discrete-time dynamic model proposed by Bischi and Baiardi (Chaos Solitons Fractals 79:145-156, 2015a). The model...