Philip Leifeld’s research while affiliated with University of Essex and other places

The exponential random graph (ERGM) model is a popular statistical framework for studying the determinants of tie formations in social network data. To test scientific theories under the ERGM framework, statistical inferential techniques are generally used based on traditional significance testing using p values. This methodology has certain limitations however such as its inconsistent behavior when the null hypothesis is true, its inability to quantify evidence in favor of a null hypothesis, and its inability to test multiple hypotheses with competing equality and/or order constraints on the parameters of interest in a direct manner. To tackle these shortcomings, this paper presents Bayes factors and posterior probabilities for testing scientific expectations under a Bayesian framework. The methodology is implemented in the R package 'BFpack'. The applicability of the methodology is illustrated using empirical collaboration networks and policy networks.

Political actors participate in policy debates as an advocacy strategy to influence political opponents and public opinion. They often engage in cross-sectoral advocacy by participating in multiple adjacent debates. To investigate what factors influence cross-sectoral advocacy in policy debates, we examined advocacy coalitions in two health policy debates in the UK – the regulation of sugar-sweetened beverages and alcoholic drinks. We predicted cross-sectoral advocacy efforts across 237 actors, such as health charities, manufacturers, or retailers, as a function of their belief system alignment relative to their advocacy coalition. In a methodological innovation, Bayesian item response models were applied to policy beliefs stated publicly by actors in eleven newspapers to measure the ideological positions of actors and beliefs relative to their advocacy coalition. Extreme belief alignment relative to one’s coalition, a small spread of stated beliefs, and a strong engagement were found to explain cross-sectoral advocacy.

Since the Treaty of Lisbon, national parliamentary chambers in the European Union can issue reasoned opinions on legislative proposals by the European Commission. These individual reasoned opinions lead to a review if at least one third of all chambers raise such concerns. Hence, coordination among parliaments is key. Using advances in inferential network analysis, this article infers the underlying diffusion pathways among national parliaments through which chambers are related to each other in their decisions to raise subsidiarity concerns. The emerging diffusion network is characterised by a compartmentalization into communities of European Union budget net contributor and net recipient countries. This descriptive finding has implications for the institutional effectiveness and aspired democratic legitimacy of the Early Warning System. A multivariate statistical network analysis confirms that diffusion occurs among net recipient countries and that weak institutions follow the lead of strong institutions in the Early Warning System.

Die Netzwerkanalyse ist eine Sammlung von Methoden zur Analyse von Interaktionen oder Beziehungen zwischen Akteuren. In der Politikwissenschaft finden diese Methoden breite Anwendung, da Politik häufig in Gruppenkontexten mit potenzieller gegenseitiger Relevanz der Akteure abläuft, während konventionelle Nicht-Netzwerk-Methoden die Unabhängigkeit (oder höchstens triviale Abhängigkeit) der Akteure in diesen Kontexten annehmen. Netzwerkanalyse erlaubt die gleichzeitige Analyse von Akteuren und ihren Beziehungen als komplexes System. Es existieren Methoden zur Beschreibung und Visualisierung von Netzwerken sowie zur statistischen Modellierung von Netzwerken. Die statistischen Methoden lassen sich grob in statische Modelle für einen beobachteten Zeitpunkt und in temporale Netzwerkmodelle unterteilen sowie in Modelle für Netzwerke oder Dyaden als abhängige Variable und Modelle für in Netzwerken geschachtelte individuelle Beobachtungen. Das Kapitel gibt einen Überblick über diese verschiedenen Methoden und ihre Anwendung in der Politikwissenschaft und stellt den aktuellen Forschungsstand vor.

In this contribution, I will examine from a cybernetics perspective how the installation of a world government would deal with global problems and crises. At the present time, this is a merely hypothetical endeavour as the prospect of a unitary world state is akin to science fiction. Yet, both scholars and practitioners have argued that the future emergence of a global government would be both likely and desirable.

Prominent current policy problems such as climate change, migration, or the financial crisis embrace a multitude of issues that are tackled within single‐ or multiple‐policy subsystems. However, interdependencies among actors that arise due to their multi‐issue engagement are often discounted when studying policy processes, including learning dynamics and alliance or trust formation among actors engaged in multiple issues. Various issues compete for actors’ attention, and actors need to choose an appropriate set of issues to deal with given their scarce resources. In this, why do actors engage in multiple issues? We present an innovative inductive approach that identifies policy issues related to Swiss water politics and actors involved therein. We use a two‐mode exponential random graph model to estimate actors’ multi‐issue activity. Results show that 39% of actors engage in more than one water‐related issue and that cross‐subsystem and homophily clustering and clustered issue popularity drive this issue engagement.

Discourse network analysis (DNA) is a combination of network analysis and qualitative content analysis. DNA has been applied to various policy processes and debates to show how policy actors are related at the discursive level, complementing coordination relations among them that are often analysed in the application of the policy networks approach. This editorial takes stock of the theoretical and methodological research frontiers in DNA and summarises the contributions of the eleven articles in the thematic issue on “Policy Debates and Discourse Network Analysis” in Politics and Governance .