A CUSUM Test for Common Trends in Large Heterogeneous Panels

Abstract A new class of multivariate nonlinear quasi-vector autoregressive (QVAR) models is introduced. It is a Markov switching score-driven model with stochastic seasonality for the multivariate t-distribution (MS-Seasonal-t-QVAR). As an extension, we allow for the possibility of having common-trends and nonlinear co-integration. Score-driven nonlinear updates of local level and seasonality are used, which are robust to outliers within each regime. We show that VAR integrated moving average (VARIMA) type filters are special cases of QVAR filters. Using exclusion, sign, and elasticity identification restrictions in MS-Seasonal-t-QVAR with common-trends, we provide short-run and long-run impulse response functions for the global crude oil market.

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The variability of urban safety performance functions for different road elements: an Italian case study

European Transport Research Review ◽

10.1186/s12544-021-00490-6 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Paolo Intini ◽

Nicola Berloco ◽

Gabriele Cavalluzzi ◽

Dominique Lord ◽

Vittorio Ranieri ◽

...

Keyword(s):

Negative Binomial ◽

Prediction Models ◽

Safety Performance ◽

Common Trends ◽

Main Research ◽

Pavement Markings ◽

Italian Case ◽

Sight Distance ◽

Safety Performance Functions ◽

Urban Safety

Abstract Background Urban safety performance functions are used to predict crash frequencies, mostly based on Negative Binomial (NB) count models. They could be differentiated for considering homogeneous subsets of segments/intersections and different predictors. Materials and methods The main research questions concerned: a) finding the best possible subsets for segments and intersections for safety modelling, by discussing the related problems and inquiring into the variability of predictors within the subsets; b) comparing the modelling results with the existing literature to highlight common trends and/or main differences; c) assessing the importance of additional crash predictors, besides traditional variables. In the context of a National research project, traffic volumes, geometric, control and additional variables were collected for road segments and intersections in the City of Bari, Italy, with 1500 fatal+injury related crashes (2012–2016). Six NB models were developed for: one/two-way homogeneous segments, three/four-legged, signalized/unsignalized intersections. Results Crash predictors greatly vary within the different subsets considered. The effect of vertical signs on minor roads/driveways, critical sight distance, cycle crossings, pavement/markings maintenance was specifically discussed. Some common trends but also differences in both types and effect of crash predictors were found by comparing results with literature. Conclusion The disaggregation of urban crash prediction models by considering different subsets of segments and intersections helps in revealing the specific influence of some predictors. Local characteristics may influence the relationships between well-established crash predictors and crash frequencies. A significant part of the urban crash frequency variability remains unexplained, thus encouraging research on this topic.

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Academic policy advice in consensus-seeking countries: the cases of Belgium and Germany

International Review of Administrative Sciences ◽

10.1177/0020852319878780 ◽

2019 ◽

pp. 002085231987878 ◽

Cited By ~ 3

Author(s):

Valérie Pattyn ◽

Sonja Blum ◽

Ellen Fobé ◽

Mirjam Pekar-Milicevic ◽

Marleen Brans

Keyword(s):

Academic Research ◽

Policy Advice ◽

Current Evidence ◽

Common Trends ◽

Policy Advisory Systems ◽

Academic Policy ◽

Advisory Systems ◽

The Government ◽

Special Case

Research on policy-advisory systems worldwide has shown that historically dominant sources of advice traditionally located in-house to the government have been increasingly supplemented by other actors and outside knowledge. However, the vast majority of research has concentrated on the anglophone context. Yet, countries with a consensus-seeking, neo-corporatist tradition provide a special case in terms of policy advice and merit more scholarly attention. What counts as evidence in these countries is the expert rationality of institutional representatives. The position and role of academic research in consensus-based systems is unclear, and is the focus of this article. Can we observe commonalities across consensus-style countries, or do differences prevail? We investigate two typical consensus-seeking countries: Belgium and Germany. To examine the supply side of policy advice, the article reviews current evidence regarding their policy-advisory systems. For the demand side, we present insights from a survey among federal ministerial officials. We find common trends between the two cases but their nature and extent are idiosyncratic. In Belgium, the supply of and demand for academic policy advice is comparatively lower, while the German case exhibits more change in the advisory landscape and institutionalisation of the supply of and demand for academic research. Points for practitioners • Countries with a consensus-seeking, neo-corporatist tradition provide a special case in terms of policy advice. • The findings suggest that there are common trends but their nature and extent are idiosyncratic. • In Belgium, the supply of and demand for academic advice is comparatively lower. • Germany’s policy-advisory landscape exhibits more change and institutionalisation of the supply of and demand for academic research.

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