Population–Employment Models: Stationarity, Cointegration, and Dynamic Adjustment

Abstract.  Population and employment in the 50 United States are found to be non‐stationary and cointegrated. Vector error correction (VEC) models exhibit dynamics with adjustment to shocks essentially completed in 30–35 years . This contrasts with adjustment periods between one and two centuries for non‐stationary models specified in levels. These dynamic adjustment patterns support the hypothesis that relatively long adjustment periods and slow dynamics are probably the spurious results of using non‐stationary levels of population and employment outside of a VEC model framework. Recommendations for modeling the population–employment relationship are offered based on the findings reported.     

Preferences for Housing, Jobs, and Commuting: A Mixed Logit Analysis

This paper reports stated preferences of Dutch workers for combinations of housing, employment, and commuting. The analysis uses standard logit models as well as mixed logit models. Estimation results offer insights into the relative importance of various aspects of housing, employment, and commuting. Households dislike commuting and the value of commuting time implied by the model is high in comparison to the wage rate. Nevertheless, preferences for some housing attributes are strong enough to make substantially longer commuting acceptable to most workers. Of special interest is the strong preference for living in small-or medium-size cities, especially among two income households. Using a mixed logit model instead of a standard logit model results in a substantial improvement of the loglikelihood, reflecting the importance of heterogeneity among respondents. If no individual characteristics are incorporated into the model, the mixed logit implies substantially lower average monetary evaluations of most attributes. These differences are much smaller if some individual characteristics are incorporated into the model.     

A Comparative Study on Ground Motion Attenuation in the 2012 Varzaghan-Ahar Doublet Event,Northwest of Iran

Predictive capabilities of the four updated NGA ground-motion models (NGA-WEST2) are evaluated in this study for acceleration response spectra using observed ground motions for August 11, 2012 Varzaghan-Ahar events in Iran. The predicted results were compared with those of regional attenuation equations and NGA08 models as well. The results of analyses revealed that the models of NGA-WEST2 improve prediction performance of NGA08 models for the two studied moderate events. All of models underestimate the recorded spectra of the second event for regionally significant period of 0.2 s at source distances below 50 km. For this distance range, almost all of the models underestimate the recorded spectra for periods larger than 1 s.     

OPTIMAL REGIONAL GROWTH MODELS: MULTIPLE OBJECTIVES, SINGULAR CONTROLS, AND SUFFICIENCY CONDITIONS

ABSTRACT We develop a generalized Harrod-Domar type of model for optimal regional growth which allows determination of the optimal allocation of regional public investments and which considers multiple growth objectives, as well as both normal and singular fiscal instruments. This general model is shown to include most of the previous optimal regional growth models as special cases. Necessary conditions for some special cases of the general model are analyzed in detail, and decision rules associated with derived optimal regional growth policies are articulated. These special cases verify that singular controls do exist in certain instances, and that they must be considered for the complete specification of optimal regional growth policies; this is significant because singular controls have not been previously analyzed in the literature. We conclude the paper with a discussion of sufficiency conditions for optimal regional growth models which is more general than that given by previous authors.     

Theoretical and Computational Links between the p-Median,Location Set-covering,and the Maximal Covering Location Problem

It has been shown that the p-median problem, the location set-covering and the maximal covering location problems are important facility location models. This paper gives a historical perspective of the development of these models and identifies the theoretical links between them. It is shown that the maximal covering location problem can be structured and solved as a p-median problem in addition to the several approaches already developed. Computational experience for several maximal covering location problems is given.     

Mass violence,trauma, and their children

This article concerns the social construction of collective memory particularly with regard to the social remembering of mass violence and trauma. How do individual memories of mass violence which are often idiosyncratic, nonverbal, and embodied coalesce and crystallize into coherent narratives shared by a group. The books reviewed here demonstrate that there are both discursive means of remembering and non-discursive means of remembering. Social memories can take narrative and textual form or they can take performative and ritual form. How does the non-discursive interact with the discursive and do these interactions depend upon varying social, political, and cultural circumstances? An encompassing theoretical issue is addressed in this literature concerning the adequacy of sociological and anthropological models in the elucidation of trauma memory vs. psychological models which place emphasis on the individual. Subsumed within this question is an inquiry into the adequacies and inadequacies of Western clinical models, such as the PTSD model, in explaining trauma due to mass violence, and the opposition frequently noted among survivors between silence and verbalization. Numerous ethnographic examples are considered in this article but particular attention is paid to the Nazi, Cambodian, and Rwandan genocides.     

Methodological Considerations in the Analysis of Residential Mobility: A Test of Duration,State Dependence,and Associated Events

This paper provides evidence that a longitudinal research methodology is particularly well suited to disentangle life-course explanations of residential mobility while controlling for the duration-of-residence effect. Much of the literature on residential mobility has yielded conflicting evidence regarding the effects of cumulative inertia, cumulative stress, and duration dependence due in large part to different methodologies and different operational conceptions of the life cycle. I argue that the lack of analytical attention directed toward the concept of the risk period, as well as the persistent use of the household, rather than the individual, as the unit of analysis, further serve to confound our understanding of residential mobility. The empirical analysis uses the Panel Study of Income Dynamics and discrete-time logistic regression models to include duration dependence, state dependence, associated events and nonstationarity in models of residential mobility for both renters and owners. Using an event-oriented data structure that links household careers and housing careers, the study is conducted in three stages: (1) important tenure differences are established using comparative survival rates, (2) discrete-time logit models of the hazard of moving, that include duration dependence and state dependence, are fitted by tenure group, and (3) the models are extended to include a change in household type as an associated event that increases (or decreases) the likelihood of moving. The findings indicate the potential of event-history analysis to advance the field of residential mobility by providing a means to assess issues that once seemed intractable.     

Employment Densities, Spatial Autocorrelation, and Subcenters in Large Metropolitan Areas

Employment density functions are estimated for 62 large metropolitan areas. Estimated gradients are statistically significant for distance from the nearest subcenter as well as for distance from the traditional central business district. Lagrange Multiplier (LM) tests imply significant spatial autocorrelation under highly restrictive ordinary least squares (OLS) specifications. The LM test statistics fall dramatically when the models are estimated using flexible parametric and nonparametric methods. The results serve as a warning that functional form misspecification causes spatial autocorrelation.     

Experimental Study and Numerical Model Calibration for Earthquake-Induced Collapse of RC Frames with Emphasis on Key Columns,Joints, and the Overall Structure

A thorough investigation of earthquake-induced collapse of reinforced concrete frames is presented. The inherent correlation between the nonlinear behavior of key components and the collapse mechanism of overall frame is examined through concurrent collapse tests of both frame and key components. Important issues in the component models are investigated through calibration against experiments, leading to a comprehensive structural system model. Both test and simulation indicate that the seismic performance are predominately governed by the key columns, whereas the energy dissipation capacity is somewhat affected by the joints. This study offers systematic experimental data and numerical models for future collapse assessments.     

Stable Isotopes,Chronology, and Bayesian Models for the Viking Archaeology of North-East Iceland

This paper reviews the results of a long-term research project that used stable isotope analyses (δ¹³C, δ¹⁵N, δ³⁴S) and Bayesian mixing models to better model the chronology for a presumed Viking Age cemetery at Hofstaðir, near Lake Mývatn in north-east Iceland. δ¹³C and radiocarbon dating indicated that many of the individuals consumed a large amount of marine protein, which results in a marine reservoir effect (MRE), making ages older than expected. In addition to the MRE, geological activity in the region has the potential to introduce massive quantities of radioactive ‘dead’ carbon into the freshwater system, resulting in a very large freshwater reservoir effect (FRE) that can offset radiocarbon ages on the order of a few thousand years. The radiocarbon dates of organisms that derive an unknown proportion of their carbon from both marine and freshwater reservoirs are extremely difficult to ‘correct’, or, more appropriately, model. The research not only highlights the complexities of dealing with multiple reservoirs, but also how important it is to develop models that are temporally and geographically relevant to the site under study. Finally, it shows how this data can be used to inform the development of chronological models for refining the dating for archaeological activity.     

Declines in Mammalian Foraging Efficiency during the Late Holocene, San Francisco Bay, California

Resource intensification models that have been posited for prehistoric California predict decreases in foraging efficiency during the late Holocene, Using implications of the fine-grained prey model of optimal foraging theory, I derive an index of the efficiency of vertebrate prey choice from the relative abundances of large- and small-sized prey items. I then test the intensification models with late Holocene mammalian faunas from San Francisco Bay shellmounds. Dramatic linear decreases in the relalive frequency of artiodactyls compared to the smaller sea otters (Enhydra lutris) throughout the occupational histories of particular localities strongly support the resource intensification models. The declines in artiodactyl abundances are not correlated with late Holocene climatic indices developed for this region, with changes in the seasonal use of shellmounds, or with technological innovations. An intra- and interregionally consistent pattern in declining abundances of large mammals in environmentally distinct regions throughout California suggests that resource depression driven by human predators may be the single most important cause of the declines. These patterns have far-reaching implications concerning the long-term human role in structuring prehistoric ecosystems.     

Paradigms,Assumptions, Enclosure,and Violence: The Hillforts of Strathdon

Abstract

This paper examines the assumptions and intellectual models that lie behind the debate around the connections between violence, warfare, and hillfort construction. These underlining academic paradigms have been heavily influenced by current social and political mores, which have created a context in which prehistoric and Early Medieval hillforts are studied in isolation and where the theoretical models have been developed from and with sole reference to the prehistoric period. In turn the debate in Scotland is based on a very limited number of dated hillforts. New excavation by the author from Aberdeenshire has allowed an attempt at an integrated settlement sequence and this is presented in the assumed context of violence as a dominant influencing factor in hillfort design and construction at specific periods.     

Substitutability,Spatial Structure,and Spatial Interaction

This paper attempts to distill the relationship among spatial structure, consumer preferences, and spatial interaction. It introduces the notion of substitutability. Destinations are substitutable in both economic-behavioral and physical-locational senses. Inadequate treatment of this can lead to variations in the estimated parameters of conventional spatial interaction models.     

AGGLOMERATION,TRADE, AND SPATIAL DEVELOPMENT: BRINGING DYNAMICS BACK IN*

ABSTRACT The field of spatial economics has made enormous progress in theorizing and measuring agglomeration effects, trade costs, and urbanization. Typical models establish structural determinants by making strong assumptions about which forces are relevant and how these forces interact. But many of these assumptions, about firms, agents, spatial costs, and market structures, are questionable. As a result, the field has a long way to go to establish causality, and to be able to account for spatial economic dynamics.     

Cultural transmission, copying errors, and the generation of variation in material culture and the archaeological record

Archaeologists are adept at analyzing variation in artifacts. The discipline has well established and tested methods to track change through time and to evaluate the function of artifacts that depend upon measures of variation in the archaeological record. Although a critical concept, the means by which variation in material culture is generated is not well understood. This paper explores one source of variation, copying errors, and systematically examines how cultural transmission processes act to amplify, reduce, or maintain such variation. Using simple models, we generate expected distributions for the amount of variation that occurs through time under varying circumstances. This variation is caused by small errors that are transmitted from one person to another in the propagation and replication of cultural traits. These baseline values provide useful null models for explaining variation in prehistoric assemblages of artifacts. We use measurements of projectile points from Owens Valley and Woodland ceramics from Illinois to demonstrate the value of this approach.     

Computer-based,automatic recording and illustration of complex archaeological artifacts

We report on the development of a computerized automatic system to illustrate complex archaeological objects. The illustrations are based on 3D scans of the artifacts. The 3D models can be automatically translated, by new algorithms specifically designed for this purpose, into 3D or 2D line drawings; into colored images that emphasize the salient shape attributes of the artifacts and of the 3D designs on them; and to images that enhance faint/eroded designs that are otherwise difficult to discern. These illustrations are intended to replace traditional, manual drawings, which are very expensive to produce and not accurate enough. Our illustrations also provide a better visualization tool than the 3D models themselves. Though 3D scanning already improves the visibility of objects and their features, it does not suffice for rapid visual recognition. Our system generates efficient, objective, accurate and simplified representations of complex objects and the designs on them from any number of required views.     

Changes in reindeer body part representation at Grotte XVI, Dordogne, France

Foraging theory models are used to examine changes in reindeer body part representation in the Middle and Upper Paleolithic ungulate assemblages at Grotte XVI (Dordogne, France). Previous research suggests that climate change resulted in progressive increases in reindeer abundances throughout the region. If increased forager encounter rates with reindeer resulted in decreased transport distances and search times, central-place forager models predict that field processing at the kill site will decline and reindeer body part transport will become less selective. This prediction is supported, and reindeer skeletal element abundances are shown to become increasingly even and incorporate higher frequencies of low utility elements through time. The progressive shift in reindeer transport strategies operates across technological and hominin species boundaries including the Middle-to-Upper Paleolithic transition.     

Conceptualizing the Regional Roles of Universities,Implications and Contradictions

The impact of universities on the economic wellbeing and innovative potential of regions has been the object of intense scholarly and policy interest in the last years. Despite this interest, a clear picture is missing in relation to the roles universities are seen to play, the benefits of university activities and the mechanisms through which they occur. This paper proposes a review and a critique of current views on the role of universities and their associated policy implications. To achieve this, the paper identifies five “models” for universities as they are reflected in the literature, each advocating different set of roles of universities, different spatial aspects of interactions, as well as different mechanisms for university engagement. National and regional innovation and research policies tend to explicitly or implicitly reflect one or a combination of several of these models, giving rise to potential contradictions or conflicts of policy rationales and objectives.     

Policy Type, Bureaucracy, and Urban Policies: Integrating Models of Urban Service Distribution

This study advances a comprehensive model of urban service distribution based upon types of urban services, to which little concern has been paid in the study of service distribution. By introducing an integrating typology of urban services, it shows how the pattern of service distribution varies depending on service type. By doing so, this study demonstrates that polarized discussions about the primacy of different explanatory models are inadequate and artificial, and that seemingly contradictory models are not necessarily mutually exclusive when the effect of service type on the distribution of services is taken into consideration.     

Models of disability,ideas of justice,and the challenge of full participation

The definitions of disability adopted in the UN Convention on the Rights of Persons with Disabilities (CRPD) necessitate an important change in the way disability is assessed and introduce a new idea of justice in relation to persons with disabilities. The article starts by reviewing the various ‘models of disability’ prevailing in the past and the respective ideas of justice underlying them. The charity model, for instance, was rooted in ideas of divine justice and human beneficence, where care for the disabled led in practice to their being segregated from the rest of society, while the medical model saw justice in terms of treatments or compensations for individual pathologies rather than of positive enablement for active living. The CRPD overturns these models and the related conceptions of justice by emphasising society's obligations towards persons with disabilities and, above all, their human right to full inclusion and participation in society. The key concepts are empowerment and capability. In Italy these concepts and this new conception of justice have started to be applied by the Osservatorio nazionale sulla condizione delle persone con disabilità, the body created to monitor the effective application of the CRPD in Italy, and they are included in the two-year action programme on disability, approved by the Italian government in October 2013.