The multiple filter test for change point detection in time series

A framework for the detection of change points in the expectation in sequences of random variables is presented. Specifically, we investigate time series with general distributional assumptions that may show an unknown number of change points in the expectation occurring on multiple time scales and that may also contain change points in other parameters. To that end we propose a multiple filter test (MFT) that tests the null hypothesis of constant expectation and, in case of rejection of the null hypothesis, an algorithm that estimates the change points.The MFT has three important benefits. First, it allows for general distributional assumptions in the underlying model, assuming piecewise sequences of i.i.d. random variables, where also relaxations with regard to identical distribution or independence are possible. Second, it uses a MOSUM type statistic and an asymptotic setting in which the MOSUM process converges weakly to a functional of a Brownian motion which is then used to simulate the rejection threshold of the statistical test. This approach enables a simultaneous application of multiple MOSUM processes which improves the detection of change points that occur on different time scales. Third, we also show that the method is practically robust against changes in other distributional parameters such as the variance or higher order moments which might occur with or even without a change in expectation. A function implementing the described test and change point estimation is available in the R package MFT.     

Is the Retail Gasoline Market Local or National?

This paper studies the effect of station density on prices in the retail gasoline market in the Czech Republic. We estimate the impact of the number of competing stations in various driving-distance ranges around each station on prices. We find that station density has a negative effect on prices; the effect decreases with distance and is statistically significant up to six kilometers. This suggests that the retail gasoline market is local rather than national.     

Systemic risk in Europe: deciphering leading measures,common patterns and real effects

The paper studies salient features of systemic risk in a sample of 22 European (EU and non-EU) countries during January 2010–March 2016. Building on a novel dataset and conducting an empirical horse race, we determine pivotal systemic risk measures for the sample countries. SRISK and volatility indicator tend to lead other metrics, followed by leverage. In contrast to the conventional wisdom, composite systemic risk measures aggregated with the aid of principal and independent component analysis perform worse. The leading systemic risk measures exhibit a high degree of connectedness. The VIX index, TED spread, the Composite Index of Systemic Stress (CISS) and long-term interest rates underlie their dynamics. Two clusters within the sample are identified, with CISS and long-term interest rates being crucial to distinguish between them. There is only scarce evidence for causal linkages between systemic risk and industrial production in the sample countries, based on the concurring results of standard and nonparametric Granger causality tests.     

Katastrophenanleihen als Risikotransfer-Instrument für Industrieunternehmen

All over the world an increase in natural catastrophes and resulting damages can be observed for entire economies as well as for individual industrial enterprises. This trend leads to extraordinary expensive traditional natural catastrophe insurance or even a lack of insurance capacities. Due to the increased threat resulting from natural catastrophes and the inefficiencies of traditional insurance solutions, it will be analyzed in the following whether catastrophe bonds (cat bonds), as an alternative risk transfer instrument, should play a role in the risk management portfolio of industrial companies. It will be discussed whether catastrophe bonds are possible risk transfer instruments for industrial companies and whether certain basic prerequisites for a confirmation of the suitability are recognizable. In a further step, the design possibilities for cat bonds will be presented and the most suitable design alternatives for industrial companies as issuers of cat bonds will be elaborated. In addition, a critical comparison between the usage of traditional insurance solutions and cat bonds by industrial companies in order to protect themselves against natural catastrophes will be conducted. The result is a first orientation and a general guideline for dealing with catastrophe bonds as part of the operational risk management for industrial companies.     

Digital insurance brokers—old wine in new bottles? How digital brokers create value

This article analyzes digital brokers in the countries of the DACH region, Germany, Austria, and Switzerland, from a business model perspective. We argue that the potential to create new value for insurance customers has not yet been fully realized. Our analysis has identified two strategic action areas. The first concerns the exploitation of the wealth of customer data available. Those digital brokers who will succeed in generating new content and services using data analytics have the potential to take customer centricity and individuality to new bounds. The second centers around introducing aspects of community, such as connecting peers and enabling them to interact. The critical success factors are volume, a high degree of automation as well as leveraging the infrastructure and data to delivering new, value-adding content and services that go beyond traditional intermediation.     

Electoral cycles in MPs’ salaries: evidence from the German states

Members of parliament (MPs) often set their own salaries. Voters dislike self-serving politicians, and politicians are keen to please voters. In line with political business cycle theories, politicians thus may delay giving themselves a salary increase until after elections. We investigate electoral cycles in the salary increases of German state MPs. Using data for 15 states over the period 1980–2014, we find no evidence that increases in MP salaries are influenced by election cycles. Politicians can increase their salaries at any point during the legislative period without negative consequences. We posit that this may be because even those voters who are most disenchanted with politics likely understand that all politicians benefit from a salary increase and thus do not punish the governing party at the polls.     

Corroborating social media echelon in cancer research

Worldwide medical facilities differ, and for this reason, the causes of death can vary. Cancer is considered the second leading cause of death after heart disease worldwide, and the same causes of death are observed in the United States (US). Therefore, the purposes of this study are to explore worldwide research levels in the field of cancer and the social collaboration of researchers and institutions in this field. This article examines the structural patterns of international co-authors and co-institutions in science citation index papers in cancer research. The study uses measures from the social network analysis method, including degree centrality, betweenness centrality, eigenvector centrality, and effectiveness, to investigate the effects of social networks in the area of cancer research. Empirical analysis results identify the US is the most central country, followed by Germany, Italy, France, and China, in terms of co-authored networks in this research field. Institutional analysis results indicate that the University of Milan is at the top in terms of degree centrality. The Gustave Roussy Cancer Campus in France and German University of Düsseldorf occupy the second and fourth positions, respectively. The University of California in Los Angeles and Harvard University, both in the US, are at third and fifth positions, respectively.     

Campaign dynamics of cognitive accessibility of political judgments: measuring the impact of campaigns and campaign events using response latencies in two German rolling cross section studies

Do campaigns matter? Based on two rolling cross-section computer-assisted telephone surveys conducted in the run-up to the 2009 and 2013 German Federal Election, we test whether we can detect campaign effects on the accessibility of voters’ judgments: how do response latencies of political judgments evolve over the course of campaigns? The study uses response latencies, i.e. the standardized time it takes respondents to answer a survey question, as a proxy measurement of cognitive accessibility of political judgments. If campaigns do help voters to make up their minds, we should be able to observe changes at the implicit level of response latencies. Do people answer questions about their voting behavior and political attitudes faster as Election Day comes closer? Our results suggest that attitudes towards candidates and voting intentions become more cognitively accessible during campaigns whereas the accessibility of party identification is conditional on the contextual features of campaigns. In addition we find specific short-term effects of TV debates.