Mark L. Burkey

Unintended Migration Consequences of US Welfare Reform

Researchers have analyzed whether US welfare reform has induced interstate migration. Empirical results are inconclusive because methodologies are based on pre-reform thinking. This paper presents a post-reform migration model. We find that recipients move to avoid harsh sanction policies, seek lenient work requirements, and extend time limits. Unlike the first two behavioral responses, the latter is controversial. Critics will argue that such moves are illegal, and violators can be prosecuted because states share data. However, only active cases are being shared, meaning violators cannot be caught. Our model produces testable hypotheses which are consistent with (and reconcile) previous empirical results.

Explaining property damage from crashes at signalized intersections

Abstract In this article, we estimate a Tobit model of property damage costs of crashes that occur at signalized intersections with data from one US city – Greensboro, North Carolina. The model includes data on technological variables, types of crash, types of vehicle, traffic and intersection characteristics, and driver condition at the time of crash. The results indicate that driver condition and type of vehicle contribute more to higher property damage costs than any other variable. Those variables that have negative effects on these costs are being a female driver, traffic volume, commercial and institutional land uses. From the results, we conclude that traffic countermeasures such as reducing the amber signal phase time and posting lower speed limits on urban roads could reduce property damage costs.

An Optimization-based Framework for Modelling Counter-terrorism Strategies

This article introduces the subject of terrorism and counter-terrorism by means of a two-person bimatrix game that provides some insight into the behaviour of the two players. We then examine three important areas in counter-terrorism tasks: the detection of terrorist cells and how to render them inoperable, the fortification of assets in order to protect them from terrorist attacks and the optimal evacuation of people from an area affected by terrorism. Basic mathematical models are formulated and demonstrated. This article concludes with some thoughts on potential extensions of the models presented here.

Voronoi Diagrams and Their Uses

Voronoi diagrams are a very simple geometrical construct with a large variety of applications. Simply put, the problem can be described as follows. Consider some d-dimensional space in which a number of given points (sometimes referred to as seeds, attractors, or generators) are located. To each seed we assign a set that includes all points that are closer to the seed it is assigned to than to any other seed. Such a set is called a Voronoi set. The collection of all Voronoi sets is then a Voronoi diagram. Voronoi diagrams can be constructed for a number of different metrics. Clearly, different metrics will lead to different measures of proximity that result in rather different Voronoi diagrams.

Location Modeling for Logistics Parks

This case study highlights issues that are faced by location theorists in solving real-world problems by drawing upon a project involving the location of a Logistics Park in the Southeastern region of North Carolina, USA. First, the location modelling is presented using standard analytical methodology from location theory. Thereafter, a structured framework, referred to by its acronym SIRC, is introduced, which can be used for real-life location modeling problems. The implementation of SIRC is then illustrated through a description of the actual process used during the implementation of the project. Finally, the case study closes with its most important section, namely, lessons learned from the project that can guide future academic research in location theory in incorporating real life factors into location modeling.