Objective methods for graphical structural learning

Graphical models are used for expressing conditional independence relationships among variables by the means of graphs, whose structure is typically unknown and must be inferred by the data at hand. We propose a theoretically sound Objective Bayes procedure for graphical model selection. Our method is based on the Expected-Posterior Prior and on the Power-Expected-Posterior Prior. We use as input of the proposed methodology a default improper prior and suggest computationally efficient approximations of Bayes factors and posterior odds. In a variety of simulated scenarios with varying number of nodes and sample sizes, we show that our method is highly competitive with, or better than, current benchmarks. We also discuss an application to protein-signaling data, which wieldy confirms existing results in the scientific literature.     

Issues in the analysis of co-authorship networks

Scientific collaboration is a complex phenomenon that improves the sharing of competences and the production of new scientific knowledge. Social Network Analysis is often used to describe the scientific collaboration patterns defined by co-authorship relationships. Different phases of the analysis of collaboration are related to: data collection, network boundary setting, relational data matrix definition, data analysis and interpretation of results. The aim of this paper is to point out some issues that arise in these different phases, highlighting: (i) the use of local archives versus international bibliographic databases; (ii) the use of different approaches for setting boundaries in a whole-network; (iii) the definition of a co-authorship data matrix (binary and weighted ties) and (iv) the analysis and the interpretation of network measures for co-authorship data. We discuss the different choices that can be made in these phases within an illustrative example on real data which is referred to scientific collaboration among researchers affiliated to an academic institution. In particular, we compare global and actor-level network measures computed from binary and weighted co-authorship networks in different disciplines.     

Market Power and Patent Strategies: Evidence from Renaissance Venice

This paper exploits the introduction of the first regularized patent system, which appeared in the Venetian Republic in 1474, to examine the factors shaping inventors’ propensity to use a new form of intellectual property. We combine detailed information on craft guilds and patents in Renaissance Venice and show a negative association between patenting activity and guild statutory norms that strongly restricted entry and price competition. Our analysis shows that the heterogeneity in patenting activity documented by the industrial organization literature is not a special feature of modern technologies, but is rather a persistent phenomenon affected by market power.     

Local banking and local economic growth in Italy: some panel evidence

This article provides new evidence on the contribution of local banking to local economic growth (i.e. at county level – the Italian ‘province’) in Italy. A comprehensive data set is used, which includes control variables for social capital and human capital as well as indicators of the quality of local infrastructures and the production structure of the local economy. A linear within-estimator technique with fixed effects is applied to a modified version of the so-called Barro regression in order to address the well-known econometric issues of reverse causality and estimation bias resulting from unobserved district-specific influences.     

Which Way is “Up” in Upgrading? Trajectories of Change in the Value Chain for South African Wine

Global Value Chain (GVC) analysis uses the concept of upgrading to highlight paths for developing country firms to “move up the value chain,” usually through the lenses of four categories—product, process, functional, and inter-sectoral upgrading. The implicit normative expectation is that these firms move toward producing higher value-added products and/or take on more sophisticated functions along a value chain. In this article, upgrading is approached more broadly as “reaching a better deal,” including a balance between rewards and risk. The case study of South African wine shows that better product quality, improved processes, and some functional upgrading have co-existed with processes of “downgrading,” higher risks, and limited rewards, especially in traditional export markets. A reflection on further conceptual development and directions for empirical research is also provided.     

Organizing the purchasing department for innovation

Innovation is by far one of the most important competitive priorities in the current business context. Companies increasingly rely on their supply base to support their innovation potential. As a consequence, the purchasing department might dramatically affect the firm??s innovation capability. This paper aims to investigate??using a multiple case study approach??how the organizational design of the purchasing department could determine a firm??s capability to foster and manage innovation. Seven highly innovative companies were visited and the structures of their purchasing departments were analyzed. Three different configurations for the purchasing department were identified and described.     

Cropland use,yields, and droughts: spatial data modeling for Burkina Faso and Niger

For countries with recurrent droughts, the design of drought impact mitigation measures could benefit from analyses of determinants of yields and prices of local crops at regional and district level. This study applies dynamic spatial panel data regression models to yields and prices of four major food crops across regions of Burkina Faso and Niger, over sample periods between 1984 and 2006. Results lend support to mainly simultaneous spatial spillovers, particularly for millet and cowpea prices and sorghum yields in Niger, and maize yields in Burkina Faso. After accounting for these effects, most crop yields are found to be weakly price‐responsive, as envisaged by a supply‐side geographical diffusion hypothesis. Seasonal rainfall elasticity estimates suggest that dominant food crops have slight advantage margins in terms of relative resilience to rainfall shortages. However, this result is to be weighed against low millet yields in Niger, and marked drops in sorghum yields during officially declared droughts in Burkina Faso.     

Cognitive flexibility and adaptive decision‐making: Evidence from a laboratory study of expert decision makers

Research Summary : How can strategic decision makers overcome inertia when dealing with change? In this article we argue that cognitive flexibility (i.e., the ability to match the type of cognitive processing with the type of problem at hand) enables decision makers to achieve significantly higher decision‐making performance. We show that superior decision‐making performance is associated with using semiautomatic Type 1 cognitive processes when faced with well‐structured problems, and more deliberative Type 2 processes when faced with ill‐structured problems. Our findings shed light on the individual‐level mechanism behind organizational adaptation and complement recent work on strategic inertia. In addition, our findings extend management studies that have stressed the relevance of cognitive flexibility for responding to the demands of increasingly open, flexible, and rapidly changing organizations. Managerial Summary : Humans are creatures of habits. We tend to prefer known courses of action over new ones. In many cases, habits are good. However, when things change in unpredictable ways, the past may not be good guidance for the future. We argue that “cognitive flexibility”—the ability of understanding when to rely on habits vs. when to explore new courses of action—enables managers to switch from a “fast” decision mode, based on habits, to a “slow,” more deliberate decision mode that facilitates the exploration of new courses of action. Managers high in cognitive flexibility reflect on the situation at hand, recognize and value diversity in viewpoints, and integrate such diversity in their own decision processes. By valuing diversity, they are more likely to overcome inertia.     

A policy analysis to promote conservation and use of small millet underutilized species in India

Despite the important role of Neglected and Underutilized Species (NUS) in diversifying agriculture, supporting traditional farming systems and improving food and nutritional security particularly in marginal lands, very little attention is being paid to their mainstreaming in national policies and institutions. Based on a detailed review of the regulatory frameworks governing the conservation, sustainable use and equitable sharing of benefits arising out of plant genetic resources and the circulation and registration of seeds and improved varieties, this paper discusses the extent to which the measures in place in India may favour or affect the conservation and use of NUS. In addition to these frameworks, in view of the major change realized by the 2013 National Food Security Act which has included coarse cereals in the country’s Public Distribution System (PDS), the paper also incorporates this latest policy in its analyses. A special focus is given to small millets, a group of species with unexploited economic and nutritional potential but extremely important for marginal communities’ food security and livelihoods. A set of policy recommendations and opportunities to explore are proposed to address the identified constraints with the purpose of creating a more supportive policy environment and enhancing the national capacity to promote NUS.