David Schmeidler’s contributions to decision theory

Theory and Decision -     

The importance of cross‐disciplinary scientific engagement in the development of quantitative procedures for aggregate safety assessments

Recent guidance on safety monitoring during drug development, issued by regulatory authorities in the United States and European Union, indicate a shift in focus towards aggregate safety monitoring and scientific evaluation of integrated safety data. The call for program‐level reviews of accumulating safety data, including from ongoing studies, provides an opportunity to leverage the scientific expertise and medical judgment of safety management teams with (a) a multidisciplinary approach, (b) quantitative frameworks to measure level of evidence, and (c) assessments that are product‐specific and driven by medical judgment. A multidisciplinary team, regularly reviewing aggregate safety data throughout the development program, is vital not only for early signal detection but also for generating a better understanding of the accumulating data and context needed for decreasing false alarms.     

Who Should Pay for Interdependent Risk? Policy Implications for Security Interdependence Among Airports

We study interdependent risks in security, and shed light on the economic and policy implications of increasing security interdependence in presence of reactive attackers. We investigate the impact of potential public policy arrangements on the security of a group of interdependent organizations, namely, airports. Focusing on security expenditures and costs to society, as assessed by a social planner, to individual airports and to attackers, we first develop a game-theoretic framework, and derive explicit Nash equilibrium and socially optimal solutions in the airports network. We then conduct numerical experiments mirroring real-world cyber scenarios, to assess how a change in interdependence impact the airports' security expenditures, the overall expected costs to society, and the fairness of security financing. Our study provides insights on the economic and policy implications for the United States, Europe, and Asia.     

The Ex-Ante Evaluation of Achieving Sustainable Development Goals

This paper describes the methodology and main results from an overall assessment on future achievement of sustainable development goals. The proposed approach consists of a model-based, looking forward composite sustainable development index—FEEM sustainability index—projected to the future. It represents a first experiment to reproduce the future dynamics of sustainable development indicators over time and worldwide and to assess future sustainability under different scenarios. The assessment presented here is relevant under different viewpoints. First, it has a very broad nature in terms of both geographical coverage and meaningfulness: it considers the multi-dimensional structure of sustainable development by combining relevant indicators belonging to economic, social and environmental pillars for the whole world. Second, the modelling framework to compute future trends of indicators relies upon a recursive-dynamic computable general equilibrium model. This is an ideal tool to look simultaneously at the development of many indicators, their potential interactions and trade-offs, and more in general to the consequences of economic development and/or policies aiming to increase performance in one or more indicators; it allows measuring the overall sustainability under alternative scenarios, across countries and over time. Finally, regarding the construction of the composite indicator, the application of fuzzy measures and Choquet integral increases substantially the model capability allowing taking into account the interactions that exist among the three main pillars of sustainability and the considered indicators.     

Online Social Networks and Trust

Social Indicators Research - We use Italian data from the Multipurpose Household Survey to explore how participation in social networking sites (SNS) such as Facebook and Twitter affects the most...     

A network analysis of student mobility patterns from high school to master’s

Human migration involves the movement of people from one place to another. An example of undirected migration is Italian student mobility where students move from the South to the Center-North. This kind of mobility has become of general interest, and this work explores student mobility from Sicily towards universities outside the island. The data used in this paper regards six cohorts of students, from 2008/09 to 2013/14. In particular, our goal is to study the 3-step migration path: the area of origin (Sicilian provinces), the regional university for the bachelor’s degree, and the regional university for the master’s. Our analysis is conducted by building a multipartite network with four sets of nodes: students; Sicilian provinces; bachelor region of studies; and the master region of studies. By projecting the students’ set onto the others, we obtain a tripartite network where the number of students represents the link weight. Results show that the big Sicilian cities—Palermo, Catania, and Messina—have different preferential paths compared to small Sicilian cities. Furthermore, the results reveal preferential paths of 3-step mobility that only, in part, reflect a south-north orientation in the transition from the region of study for the bachelor degree to that for the master’s.

     

Threshold‐free estimation of functional antibody titers of a group B streptococcus opsonophagocytic killing assay

Opsonophagocytic killing assays (OPKA) are routinely used for the quantification of bactericidal antibodies in blood serum samples. Quantification of the OPKA readout, the titer, provides the basis for the statistical analysis of vaccine clinical trials having functional immune response endpoints. Traditional OPKA titers are defined as the maximum serum dilution yielding a predefined bacterial killing threshold value, and they are estimated by fitting a dose‐response model to the dilution‐killing curve. This paper illustrates a novel definition of titer, the threshold‐free titer, which preserves biological interpretability while not depending on any killing threshold or on a postulated shape of the dose‐response curve. These titers are shown to be more precise than the traditional threshold‐based titers when using simulated and experimental group B streptococcus OPKA experimental data. Also, titer linearity is shown to be not measurable when using threshold‐based titers, whereas it becomes measurable using threshold‐free titers. The biological interpretability and operational characteristics demonstrated here indicate that threshold‐free titers are an appropriate tool for the routine analysis of OPKA data. Copyright © 2015 John Wiley & Sons, Ltd.     

See you on Facebook! A framework for analyzing the role of computer-mediated interaction in the evolution of social capital

Empirical studies have documented a decline in indicators of social participation in the last five decades. The responsibility of social disengagement has often been attributed to pervasive busyness and the increasing pressure on time. In this paper we argue that computer-mediated interaction, and particularly online networking, can help mitigate this downward trend. We develop a logical framework for assessing the role of the Internet in the evolution of social participation. We analyze an economy where agents can develop their social interactions through two main modes of participation, one encompassing both online networking and face to face interactions, and the other solely based on physical encounters. We study the interdependence between the increase in the pressure on time and the variation in the relative performance of the two strategies of participation.