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Criminal Network Formation and Optimal Detection Policy: The Role of Cascade of Detection
Liuchun Deng, Yufeng Sun
Journal of Economic Behavior and Organization,
September
2017
Abstract
This paper investigates the effect of cascade of detection, how detection of a criminal triggers detection of his network neighbors, on criminal network formation. We develop a model in which criminals choose both links and actions. We show that the degree of cascade of detection plays an important role in shaping equilibrium criminal networks. Surprisingly, greater cascade of detection could reduce ex ante social welfare. In particular, we prove that full cascade of detection yields a weakly denser criminal network than that under partial cascade of detection. We further characterize the optimal allocation of the detection resource and demonstrate that it should be highly asymmetric among ex ante identical agents.
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Im Fokus: Interkommunale Kooperation ist deutlich im Kommen – Ergebnisse einer Kommunalbefragung des IWH und der Universität Kassel
Martin T. W. Rosenfeld, Ivo Bischoff, C. Bergholz, Simon Melch, Peter Haug, F. Blaeschke
Wirtschaft im Wandel,
No. 1,
2016
Abstract
Interkommunale Kooperation wird vielfach als ein Mittel angesehen, mit dem speziell Städte und Gemeinden außerhalb der großen Ballungsräume die Folgen des demographischen Wandels und des zunehmenden interregionalen Standortwettbewerbs besser bewältigen könnten. Obschon immer mehr Gemeinden bei ihrer Aufgabenerfüllung zusammenarbeiten, fehlen für Deutschland bislang großflächige empirische Untersuchungen zum Phänomen der interkommunalen Kooperation. Der vorliegende Beitrag stellt Ergebnisse aus einer Befragung von 6 745 Gemeinden abseits der großen Ballungsräume zu ihrem Kooperationsverhalten in den Aufgabenbereichen Allgemeine Verwaltung, Bauhof und Tourismusmarketing vor. Die Auswertung der 1 321 Antworten gewährt aktuelle Einblicke in Merkmale und Tendenzen der interkommunalen Zusammenarbeit. Es werden unter anderem Befunde zum räumlichen, zeitlichen und thematischen Auftreten sowie zu den dahinterstehenden Rechtsformen und Motiven vorgestellt. Abschließend wird ein Ausblick auf die Möglichkeiten gegeben, mit den erhobenen Daten die Fragen nach den Wirkungen und den Bedingungen für das Zustandekommen von interkommunaler Kooperation zu beantworten.
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Testing for Structural Breaks at Unknown Time: A Steeplechase
Makram El-Shagi, Sebastian Giesen
Computational Economics,
No. 1,
2013
Abstract
This paper analyzes the role of common data problems when identifying structural breaks in small samples. Most notably, we survey small sample properties of the most commonly applied endogenous break tests developed by Brown et al. (J R Stat Soc B 37:149–163, 1975) and Zeileis (Stat Pap 45(1):123–131, 2004), Nyblom (J Am Stat Assoc 84(405):223–230, 1989) and Hansen (J Policy Model 14(4):517–533, 1992), and Andrews et al. (J Econ 70(1):9–38, 1996). Power and size properties are derived using Monte Carlo simulations. We find that the Nyblom test is on par with the commonly used F type tests in a small sample in terms of power. While the Nyblom test’s power decreases if the structural break occurs close to the margin of the sample, it proves far more robust to nonnormal distributions of the error term that are found to matter strongly in small samples although being irrelevant asymptotically for all tests that are analyzed in this paper.
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The Halle Economic Projection Model
Sebastian Giesen, Oliver Holtemöller, Juliane Scharff, Rolf Scheufele
Economic Modelling,
No. 4,
2012
Abstract
In this paper we develop an open economy model explaining the joint determination of output, inflation, interest rates, unemployment and the exchange rate in a multi-country framework. Our model -- the Halle Economic Projection Model (HEPM) -- is closely related to studies published by Carabenciov et al. Our main contribution is that we model the Euro area countries separately. In doing so, we consider Germany, France, and Italy which represent together about 70 percent of Euro area GDP. The model combines core equations of the New-Keynesian standard DSGE model with empirically useful ad-hoc equations. We estimate this model using Bayesian techniques and evaluate the forecasting properties. Additionally, we provide an impulse response analysis and a historical shock decomposition.
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Warum exportiert der Osten so wenig? Eine empirische Analyse der Exportaktivitäten deutscher Bundesländer
Götz Zeddies
AStA - Wirtschafts- und Sozialstatistisches Archiv,
No. 4,
2009
Abstract
In the aftermath of re-unification, East German exports declined around 70% due to the breakdown of COMECON trade. Although since the mid-1990s export growth rates of the New Federal States were higher than those of their West German counterparts, export performance of East German States measured by the share of exports in GDP is still comparatively poor. Whereas for a long time the low export performance of East German producers was ascribed to competitive disadvantages, in the meantime structural deficits on the micro and/or macro level are often considered as the main reason. Using bilateral trade data of German Federal States, the present paper shows on the basis of an orthodox gravity model of trade that East German exports are explicitly lower than predicted by the model. But if the gravity model is augmented by additional variables representing structural differences between Federal States, the latter explain almost entirely the lower export performance of Eastern Germany. Thus, especially the smaller firm sizes and the lower shares of manufacturing industries in gross value added are identified as important explanatory factors of the comparatively weak export performance of the New German States.
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