Identification of Interaction Effects in Survey Expectations: A Cautionary Note

A growing body of literature reports evidence of social interaction effects in survey expectations. In this note, we argue that evidence in favor of social interaction effects should be treated with caution, or could even be spurious. Utilizing a parsimonious stochastic model of expectation formation and dynamics, we show that the existing sample sizes of survey expectations are about two orders of magnitude too small to reasonably distinguish between noise and interaction effects. Moreover, we argue that the problem is compounded by the fact that highly correlated responses among agents might not be caused by interaction eects at all, but instead by model-consistent beliefs. Ultimately, these results suggest that existing survey data cannot facilitate our understanding of the process of expectations formation.Survey expectations; model-consistent beliefs; social inter- action; networks.

A Note on institutional hierarchy and volatility in financial markets

From a statistical point of view, the prevalence of non-Gaussian distributions in nancial returns and their volatilities shows that the Central Limit Theorem (CLT) often does not apply in nancial markets. In this paper we take the position that the independence assumption of the CLT is violated by herding tendencies among market participants, and investigate whether a generic probabilistic herding model can reproduce non-Gaussian statistics in systems with a large number of agents. It is well-known that the presence of a herding mechanism in the model is not sucient for non-Gaussian properties, which crucially depend on the details of the communication network among agents. The main contribution of this paper is to show that certain hierarchical networks, which portray the institutional structure of fund investment, warrant non-Gaussian properties for any system size and even lead to an increase in system-wide volatility. Viewed from this perspective, the mere existence of nancial institutions with socially interacting managers contributes considerably to nancial volatility.Herding; financial volatility; networks; core-perifery

Diversification Patterns in the Growth of Firms: Evidence from Italian Manufacturing

We present empirical evidence on diversification patterns in Italian manufacturing firms and detect a robust relationship between firm size and diversification levels, with an elasticity of diversification that does not depend on firm size and is well below unity. Diversification does not lead to decreased corporate risk when measured in terms of the growth performance of Italian manufacturing firms. The findings support the Penrosian theory of diversification in the process of firm growth. In addition, we also speculate about the role of technology in the size-diversification nexus.

Factor Analysis and Predictive Ability of a Teacher-Completed Autism Rating Scale in an Urban School Setting

Autism screening tools have not traditionally been developed for use in an urban setting with students of minority status or from a low SES home. Scales have also traditionally lacked a focus on school behaviors. The Social Communication Screener for Schools (SCSS) was developed in order to assist school psychologists in an urban school setting in referring students who, following a full evaluation, were most likely to qualify for an educational diagnosis of Autism. The goal of the scale was to focus on using teacher ratings of language-based behaviors in the school setting to assess behaviors linked with Autism. The SCSS was analyzed in terms of internal consistency and overall sensitivity and specificity. The scale was revised according to initial exploratory analysis. Updated scales were developed and analyzed for specificity and sensitivity according to data-based decision rules. Results of the final analysis indicate the SCSS reached high levels of sensitivity for both age groups analyzed (7 and younger; 8 and older)

The small core of the German corporate board network: New evidence from 2010

Milakovic, Alfarano and Lux (2010) have identified a small core of directors who are both highly central to the entire network of German corporate boards as well as closely connected among themselves. While their analysis has been based on data for the management and supervisory boards of a sample of 287 publicly traded companies with high market capitalization as of May 2008, a subsequent study by Milakovic, Raddant and Birg (2010) using somewhat smaller samples from the years 1993, 1999, and 2005 has confirmed that this closely connected core is a persistent stylized fact for the German corporate sector. In this note, we provide an update of our previous results using the composition of management and supervisory boards as of December, 2010. Again, almost all qualitative properties of previous samples are confirmed despite considerable turnover within the group of persons constituting the network core

The Small Core of the German Corporate Board Network

We consider the current bipartite graph of German corporate boards and identify a small core of directors who are highly central in the entire network while being densely connected among themselves. To identify the core, we compare the actual number of board memberships to a random benchmark, focusing on deviations from the benchmark that span several orders of magnitude. It seems that the board appointment decisions of largely capitalized companies are the driving force behind the existence of a core in Germany’s board and director network. Conditional on being a board member, it is very improbable to obtain a second membership, but multiple board membership becomes increasingly likely once this initial barrier is overcome. We also present a simple model that describes board appointment decisions as a trade-off between social capital and monitoring abilit

Diversification patterns in the growth of firms: Evidence from Italian manufacturing

We present empirical evidence on diversification patterns in Italian manufacturing firms and detect a robust relationship between firm size and diversification levels, with an elasticity of diversification that does not depend on firm size and is well below unity. Diversification does not lead to decreased corporate risk when measured in terms of the growth performance of Italian manufacturing firms. The findings support the Penrosian theory of diversification in the process of firm growth. In addition, we also speculate about the role of technology in the size-diversification nexus