Two‐regime Pattern in Human Mobility: Evidence from GPS Taxi Trajectory Data

Research on complex systems has identified various aggregate relationships in phenomena that describe these systems. Travel length has been characterized by negative power distributions. Controversy, however, exists over whether mobility patterns can be modeled in terms of a simple power law (Lévy flight model) or that more complicated power laws (exponential power law, truncated Pareto) are required. This study concentrates on two issues: testing the validity of exponential power laws and truncated Pareto distributions in urban systems to describe aggregate mobility patterns, and examining differences in mobility patterns for different travel purposes. The article describes the results of an analysis of Global Positioning System (GPS) taxi trajectory data, collected in Guangzhou, China, to identify mobility patterns in the city. The least squares statistic is used to estimate the parameters of the distribution functions. Results suggest that a fusion of functions, based on an exponential power law and a truncated Pareto distribution, represents the travel time distribution best. Moreover, the findings of this study indicate different mobility patterns to exist for different travel purposes.     

Hierarchical Information Integration Applied to Residential Choice Behavior

The method of hierarchical information integration can be applied to the study of complex decision-making processes in which preference formation is influenced by many attributes of choice alternatives. In this paper, we extend Louviere's (1984) original approach to include the modeling choice processes in addition to judgment processes. Assumptions underlying the original and our extension are discussed and the new method is applied in an analysis of residential choice behavior.     

Multidimensional Sequence Alignment Methods for Activity‐Travel Pattern Analysis: A Comparison of Dynamic Programming and Genetic Algorithms

Quantitative comparisons of space‐time activity‐travel patterns have been made at length in regional science. Traditionally, Euclidean Hamming distances have been widely used to measure the similarity between activity‐travel patterns that involve several attribute dimensions such as activity type, location, travel mode, accompanying person, etc. Other techniques, such as pattern recognition in signal processing theory, have also been introduced for this purpose. All these measures, however, lack the ability to capture the sequential information embedded in activity‐travel patterns. Recently, the sequence alignment methods (SAMs), developed in molecular biology that are concerned with the distances between DNA strings, have been introduced in time use research. These SAMs do capture the similarity of activity‐travel patterns, including sequential information, but based on a single attribute only. Unfortunately, the extension of the unidimensional SAMs to a multidimensional method induces the problem of combinatorial explosion. To solve this problem, this paper introduces effective heuristic methods for the comparison of multidimensional activity‐travel patterns. First, following a brief review of existing measures of activity‐travel pattern comparison, the problem of multidimensional sequential information comparison and the combinatorial nature of the method are discussed. The paper then develops alternative multidimensional SAMs employing heuristics based on dynamic programming and genetic algorithms, respectively. These heuristic SAMs are compared using empirical activity‐travel pattern data. The paper ends by discussing avenues of future research.     

Space–Time Accessibility Under Conditions of Uncertain Travel Times: Theory and Numerical Simulations

Recently, several accessibility measures using the space–time prism concept have been suggested in the literature. These measures fail to take into account (i) the ability of individuals to adjust their activity–travel patterns in coping with constrained choice sets, (ii) uncertainty in the perception of travel times, (iii) temporal variability of travel times, and (iv) the influence of travel information on accessibility. The aim of the present article is to contribute to this literature by addressing these four shortcomings. Theory will be developed and illustrated using numerical simulations. The results suggest that the accessibility measure proposed in this article is a useful indicator of social inclusion in terms of the time individuals can spend to conduct their preferred activities. Moreover, accessibility is found to be affected by the presence of schedule delay penalties, restrictions in time allocation to activities, and the provision of travel time information in order to reduce uncertainty.     

Institutional Change in Land Planning: Two Cases from Galicia

Why do societies implement land policies? A number of arguments have been put forward in the literature, ranging from economic conceptions based on market failure and the problem of negative externalities to a more social conception based on welfare distribution and collaborative planning. However, neither all societies with similar market failures or negative externalities develop and implement land planning nor implemented land planning always results from collaborative planning. The arguments found in the literature seem not to fit the reality and, in most cases, cannot explain why societies create or undertake innovations in land planning. Within the framework of institutional change theory and based on the analysis of the emergence of two land planning devices—a land use law and a land banking law—in Galicia, Northwest Spain, this paper argues that land planning is developed to tackle negative outcomes of former institutional setups. However, the negativity of such outcomes is measured not in terms of economic performance, but in terms of social acceptance. The search for a workable definition of property within the Galician society seems to be the main driver of institutional change in land use planning analysed in this paper.     

Tetrahedron baked-clay objects from an early woodland context at the Jaketown site,Mississippi

Excavations undertaken in 1951 at the Jaketown site revealed a dense deposit of fragmented and intact pyramid-shaped baked-clay objects (BCOs) at the base of Mound A. This deposit was associated with the site’s Early Woodland component. Recent fieldwork at Jaketown also encountered the same tetrahedron deposit and identified an additional and distinct pit feature filled with the objects. In this article, we present the results of analyses that examine the production, composition, chronology, and function of these enigmatic baked-clay artifacts. Following a hiatus associated with massive flooding in the Mississippi Valley ca. 3200–2850 cal B.P., Jaketown was re-occupied by people who shared ceramic affinities with groups to the south and to the east and, who like many contemporaries, used BCOs as a part of their cooking technology. The tetrahedron deposit represents one of the earliest dated Tchula contexts at ca. 2600 cal B.P., and was used over a short time for a social purpose that brought populations together for food consumption as a means of encouraging cooperation.     

Regional skill relatedness: towards a new measure of regional related diversification

ABSTRACT

This paper proposes a novel index of regional skill-relatedness and calculates this measure for all Norwegian labour-market regions. Studies of regional related diversification rely on measures of related variety, which build on the industry classification hierarchy. However, the growing literature identifying similarities in knowledge and competences across industries demonstrates that these classifications fail to identify a great deal of actual skill relatedness, and that measures based on empirical measures of industry relatedness are required. The skill relatedness measure builds on labour mobility flows across industries to develop a relatedness matrix for Norwegian industries. It further uses social network analysis to identify the number of other regional industries to which each industry in a particular region is related. Comparing this measure to the related variety index, the analysis shows that the two measures are highly correlated, but that the regional skill relatedness index is able to identify more of the relatedness across industries. In particular, the related variety index tends to underestimate the level of relatedness in many of Norway’s most technologically sophisticated manufacturing regions, whereas these rank highly in the regional skill relatedness index. Consequently, the regional skill relatedness index represents a promising new tool for identifying relatedness in regional systems.     

Policy Punctuations and Issue Diversity on the European Council Agenda

The European Council is the highest political body of the European Union and the main venue for setting the agenda on high politics. Using a new dataset of all content‐coded European Council Conclusions issued between 1975 and 2010, we analyze the policy agenda of the European Council and test hypotheses on agenda change and diversity over time. We find that the theory of punctuated equilibrium applies to the agenda of the European Council, which exhibits a degree of kurtosis similar to that found in policy agendas of other institutions located at the juncture between input and output of the policy process. Throughout the 36‐year period, agenda‐setting dynamics involved both small changes and major shifts but also more frequent medium‐sized negative changes than found elsewhere. Given capacity limits to the agenda, large expansions of attention to topics involved large cuts in attention. Cuts were more often medium in size in order to maintain some level of attention to the topics affected, even though issue disappearance from the European Council agenda has been frequent too. This relates to the functions of the European Council as venue for high politics, with expectations about issue attendance rising with increasing policy jurisdictions throughout the European integration process. Studying dynamics over time, we measured entropy to show how the agenda became more diverse but also displayed episodic concentration in an oscillating pattern. This can be accounted for by the nature of the European Council as a policy venue: increasing complexity of this institution pushed the members to produce a more diverse agenda, but capacity limits and the need to be responsive to incoming information led to concentration at specific time‐points.     

The Validity of Hierarchical Information Integration Choice Experiments to Model Residential Preference and Choice

Integrated conjoint choice models have recently been introduced in the consumer choice literature as an approach to include a large number of influential attributes in a choice experiment and statistically test its assumed hierarchical structure. In the present article, the validity of integrated conjoint choice models is tested using housing choice as an example. The results of this study suggest that the parameters of housing utility functions derived from integrated conjoint choice models are not statistically different across experiments nor are they different from those derived from nonhierarchical conjoint models. This yields support for the validity of these models. Implications of these findings are discussed.