Erez Hatna
Erez Hatna
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Clinical Associate Professor of Epidemiology
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Professional overview
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Dr. Erez Hatna works in the fields of geoinformatics, spatial analysis, agent-based modeling, and studies urban dynamics, residential segregation, scaling laws of urban systems, and infectious disease modeling.
Dr. Hatna studies ethnic and economic residential patterns of cities using agent-based computational models of relocating households. The models simulate the formation of residential patterns as an outcome of relocation decisions of households. Dr. Hatna also studies the statistical regularities of urban systems and urban scaling. His research focuses on how the choice of urban boundaries influences the scaling relationships.
At NYU, Dr. Hatna is part of the Agent-based Modeling Lab, which works with large-scale epidemic models and cognitively plausible agents in order to produce a transformative synthesis for global public health modeling. Previously, he has conducted research at Wageningen University, University College London, and Johns Hopkins University.
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Education
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PhD, Geography, Tel Aviv University, Tel Aviv, IsraelMA, Geography, Tel Aviv University, Tel Aviv, Israel
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Areas of research and study
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Agent-Based ModelingEpidemiologyGeographic Information Science (GIS)Geospatial MethodsInfectious DiseasesMathematical and Computational ModelingModeling Social and Behavioral DynamicsUrban Informatics
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Publications
Publications
Abandonment and Expansion of Arable Land in Europe
AbstractHatna, E., & Bakker, M. M. (n.d.).Publication year
2011Journal title
EcosystemsVolume
14Issue
5Page(s)
720-731AbstractAbandonment of arable land is often assumed to happen mostly in marginal areas where the conditions for arable cultivation are relatively unfavorable, whereas arable expansion is expected to occur mostly in areas with favorable conditions. This assumption, used in many land-use change forecasts, was never properly tested, mainly because the relatively short period of full-coverage land-use inventories did not allow a systematic analysis of the phenomena. With the recent release of CORINE 2006 this has changed. In this article, we explore the typical locations of abandonment and expansion of arable land in Europe during the period 1990-2006 by means of logistic regressions. More specifically, we test whether or not locations of abandonment and expansion can be inferred from the location characteristics of arable land in 1990. If the above assumption holds, this should be the case. We demonstrate that although arable expansion indeed happens in locations that resemble the bulk of arable land in 1990 (the presumably favorable locations), arable abandonment does not necessarily happen in locations that resemble the bulk of uncultivated land (that is, the presumably unfavorable locations). In other words, the assumption does not hold. Particularly, areas close to the road network were found to be associated with both high abandonment rates and high expansion rates, which suggest that abandonment is not limited to areas that are marginal in terms of agricultural production.Agent-based modeling of householders' migration behavior and its consequences
AbstractBenenson, I., Omer, I., & Hatna, E. (n.d.).Publication year
2003Journal title
Contributions to EconomicsPage(s)
97-115AbstractThe Agent-Based approach is the most promising among the modelling techniques developed in recent decades that apply to demography and the social sciences. The current paper considers this approach with respect to householder migration and dynamics of residential distribution. It begins with a characterization of different styles of AB modelling and proceeds with examples of AB models of residential behavior, ranging from Schelling-type abstract models to real-world simulations of the population dynamics of an urban region with a population of 30,000. The latter is investigated in depth.An Agent-Based Model to Assess Possible Interventions for Large Shigellosis Outbreaks
AbstractHatna, E., Shin, J., Devinney, K., Latash, J., Reddy, V., Nivin, B., Masor, A., & Greene, S. K. (n.d.).Publication year
2024Journal title
Journal of Artificial Societies and Social SimulationIssue
27Abstract~An agent-based model to assess possible interventions for large shigellosis outbreaks
AbstractHatna, E., Shin, J., Devinney, K., Latash, J., Reddy, V., Nivin, B., Masor, A., & Greene, S. K. (n.d.).Publication year
2024Journal title
JASSSVolume
27Issue
3AbstractLarge outbreaks of Shigella sonnei among children in Haredi Jewish (ultra-Orthodox) communities in Brooklyn, New York have occurred every 3–5 years since at least the mid-1980s. These outbreaks are partially attributable to large numbers of young children in these communities, with transmission highest in child care and school settings, and secondary transmission within households. As these outbreaks have been prolonged and difficult to control, we developed an agent-based model of shigellosis transmission among children in these communities to support New York City Department of Health and Mental Hygiene staff. Simulated children were assigned an initial susceptible, infectious, or recovered (immune) status and interacted and moved between their home, child care program or school, and a community site. We calibrated the model according to observed case counts as reported to the health department. Our goal was to better understand the efficacy of existing interventions and whether limited outreach resources could be focused more effectively. We evaluated how well disseminating hand washing education in child care programs can reduce the number of infected children. The model indicated that intervention efficacy may be as high as 24% when all intervention parameters are at optimal values but only approximately 7% for a more realistic, less stringent scenario. We ranked intervention parameters according to their permutation importance using a random-forest regression analysis. The most important parameter was the minimum number of reported cases in a child care program that triggers a visit to disseminate hand washing education, followed by the use of non-antibacterial soap in hand washing education, the number of additional visits to child care programs, and the probability of successfully obtaining information on child care program attendance via patient interview. Additional strategies should be considered, such as working with community partners to assist with hand hygiene education at facilities during an outbreak.Assessing spatial uncertainties of land allocation using a scenario approach and sensitivity analysis : A study for land use in Europe
AbstractVerburg, P. H., Tabeau, A., & Hatna, E. (n.d.).Publication year
2013Journal title
Journal of Environmental ManagementVolume
127Page(s)
S132-S144AbstractLand change model outcomes are vulnerable to multiple types of uncertainty, including uncertainty in input data, structural uncertainties in the model and uncertainties in model parameters. In coupled model systems the uncertainties propagate between the models. This paper assesses uncertainty of changes in future spatial allocation of agricultural land in Europe as they arise from a general equilibrium model coupled to a spatial land use allocation model. Two contrasting scenarios are used to capture some of the uncertainty in the development of typical combinations of economic, demographic and policy variables. The scenario storylines include different measurable assumptions concerning scenario specific drivers (variables) and parameters. Many of these assumptions are estimations and thus include a certain level of uncertainty regarding their true values. This leads to uncertainty within the scenario outcomes. In this study we have explored how uncertainty in national-level assumptions within the contrasting scenario assumptions translates into uncertainty in the location of changes in agricultural land use in Europe. The results indicate that uncertainty in coarse-scale assumptions does not translate into a homogeneous spread of the uncertainty within Europe. Some regions are more certain than others in facing specific land change trajectories irrespective of the uncertainty in the macro-level assumptions. The spatial spread of certain and more uncertain locations of land change is dependent on location conditions as well as on the overall scenario conditions. Translating macro-level uncertainties to uncertainties in spatial patterns of land change makes it possible to better understand and visualize the land change consequences of uncertainties in model input variables.Assessing spatial uncertainties of land allocation using the scenario approach and sensitivity analysis
AbstractTabeau, A., Hatna, E., & Verburg, P. (n.d.).Publication year
2010Abstract~At the Boundary of Law and Software : Toward Regulatory Design with Agent-Based Modeling
AbstractBenthall, S., Tschantz, M. C., Hatna, E., Epstein, J. M., & Strandburg, K. J. (n.d.).Publication year
2022Journal title
CEUR Workshop ProceedingsVolume
3182AbstractComputer systems that automate the making of decisions about people must be accountable to regulators. Such accountability requires looking at the operation of the software within an environment populated with people. We propose to use agent-based modeling (ABM) to model such environments for auditing and testing purposes. We explore our proposal by considering the use of ABM for the regulation of ad targeting to prevent housing discrimination.Building a city in vitro : The experiment and the simulation model
AbstractHatna, E., & Benenson, I. (n.d.).Publication year
2007Journal title
Environment and Planning B: Planning and DesignVolume
34Issue
4Page(s)
687-707AbstractAll current urban models accept the 'first-order recursion' view, namely, that the state of an urban system at time t is sufficient for predicting its state at t + 1. This assumption is not at all evident in the case of urban development, where the behavior of developers and planners is defined by the complex interaction between long-term and short-term plan guidelines, local spatial and temporal conditions, and individual entrepreneurial activity and cognition. In this paper we validate the first-order recursion approach in an artificial game environment: thirty geography students were asked to construct a 'city' on the floor of a large room, with each student using the same set of fifty-two building mock-ups. Based on the analysis of game outcomes, the first-order recursive set of behavioral rules shared by all the participants is estimated and further employed for computer generation of artificial cities. Comparison between the human-built and model patterns reveals that the constructed set of rules is sufficient for representing the dynamics of the majority of experimental patterns; however, the behavior of some participants differs and we analyze these differences. We consider this experiment as a preliminary yet important step towards the adequate modeling of decision-making behavior among real developers and planners.Changing environmental characteristics of European cropland
AbstractHatna, E., Bakker, M. M., Hatna, E., Kuhlman, T., & Mücher, C. A. (n.d.).Publication year
2011Journal title
Agricultural SystemsVolume
104Issue
7Page(s)
522-532AbstractThe spatial configuration of agricultural systems is continuously changing in response to changes in demand for agricultural goods, changes in the level of competition between different land use activities, and progress in agricultural technology. This may lead to a change in the location of agricultural systems and consequently to a change in their average environmental characteristics. This paper explores the change in environmental characteristics of cropland (horticulture and field crops) over the years 1950, 1990 and 2000, for Western and Eastern Europe, using basic descriptive statistics. Underlying mechanisms are explored with logistic (interaction) regression analysis.We find that in both Eastern and Western Europe, crop cultivation shifted away from cities. In Western Europe cropland became situated on shallower soils, steeper slopes, and drier and less accessible areas. Probable reasons are that technical progress reduced the importance of traditional constraints such as drought, poor soils, and distance from markets, so that crop farmers were allowed to move to warm and sunny areas where potential productivity is highest. In addition, cropland probably lost some of its competitive power to grassland and nature. In Eastern Europe cropland concentrated on deeper soils and flatter terrain from 1990 onward. Here, the abandonment of the central planning system and a more flexible land market must have allowed a shift of cropland towards more suitable locations.Cities and regions in Britain through hierarchical percolation
AbstractArcaute, E., Molinero, C., Hatna, E., Murcio, R., Vargas-Ruiz, C., Masucci, A. P., & Batty, M. (n.d.).Publication year
2016Journal title
Royal Society Open ScienceVolume
3Issue
4AbstractUrban systems present hierarchical structures at many different scales. These are observed as administrative regional delimitations which are the outcome of complex geographical, political and historical processes which leave almost indelible footprints on infrastructure such as the street network. In this work, we uncover a set of hierarchies in Britain at different scales using percolation theory on the street network and on its intersections which are the primary points of interaction and urban agglomeration. At the larger scales, the observed hierarchical structures can be interpreted as regional fractures of Britain, observed in various forms, from natural boundaries, such as National Parks, to regional divisions based on social class and wealth such as the well-known North– South divide. At smaller scales, cities are generated through recursive percolations on each of the emerging regional clusters. We examine the evolution of the morphology of the system as a whole, by measuring the fractal dimension of the clusters at each distance threshold in the percolation. We observe that this reaches a maximum plateau at a specific distance. The clusters defined at this distance threshold are in excellent correspondence with the boundaries of cities recovered from satellite images, and from previous methods using population density.City boundaries and the universality of scaling laws
AbstractHatna, E. (n.d.).Publication year
2013Journal title
arXivAbstract~Combining segregation and integration : Schelling model dynamics for heterogeneous population
AbstractHatna, E., & Benenson, I. (n.d.).Publication year
2015Journal title
JASSSVolume
18Issue
4AbstractThe Schelling model is a simple agent-based model that demonstrates how individuals’ relocation decisions can generate residential segregation in cities. Agents belong to one of two groups and occupy cells of rectangular space. Agents react to the fraction of agents of their own group within the neighborhood around their cell. Agents stay put when this fraction is above a given tolerance threshold but seek a new location if the fraction is below the threshold. The model is well-known for its tipping point behavior: an initially random (integrated) pattern remains integrated when the tolerance threshold is below 1/3 but becomes segregated when the tolerance threshold is above 1/3. In this paper, we demonstrate that the variety of the Schelling model’s steady patterns is richer than the segregation–integration dichotomy and contains patterns that consist of segregated patches of each of the two groups, alongside areas where both groups are spatially integrated. We obtain such patterns by considering a general version of the model in which the mechanisms of the agents' interactions remain the same, but the tolerance threshold varies between the agents of both groups. We show that the model produces patterns of mixed integration and segregation when the tolerance threshold of an essential fraction of agents is either low, below 1/5, or high, above 2/3. The emerging mixed patterns are relatively insensitive to the model’s other parameters.Combining segregation and integration: Schelling model dynamics for heterogeneous population
AbstractHatna, E., & Benenson, I. (n.d.).Publication year
2014Journal title
arXivAbstractThe Schelling model is a simple agent based model that demonstrates how individuals' relocation decisions generate residential segregation in cities. Agents belong to one of two groups and occupy cells of rectangular space. Agents react to the fraction of agents of their own group within the neighborhood around their cell. Agents stay put when this fraction is above a given tolerance threshold but seek a new location if the fraction is below the threshold. The model is well known for its tipping point behavior: an initial random (integrated) pattern remains integrated when the tolerance threshold is below 1/3 but becomes segregated when the tolerance threshold is above 1/3. In this paper, we demonstrate that the variety of the Schelling model steady patterns is richer than the segregation-integration dichotomy and contains patterns that consist of segregated patches for each of the two groups alongside patches where both groups are spatially integrated. We obtain such patterns by considering a general version of the model in which the mechanisms of agents' interactions remain the same but the tolerance threshold varies between agents of both groups. We show that the model produces patterns of mixed integration and segregation when the tolerance threshold of most agents is either below the tipping point or above 2/3. In these cases, the mixed patterns are relatively insensitive to the model's parameters.Complex artificial environments - ESLab's experience
AbstractPortugali, J., Benenson, I., Omer, I., Fabrikant, R., Kasakin, H., Martens, K., Agmon, T., Birfur, S., Goldblatt, R., Hatna, E., Kharbash, V., Margalit, T., Munk-Vitelson, H., Nizry, G., Or, U., Porat, A., Roz, A., Talmor, K., & Winograd, M. (n.d.).Publication year
2006Page(s)
95-115AbstractThe Environmental Simulation Laboratory (ESLab) is one of several laboratories, research centers and planning and design organizations that have emerged in the last two decades with a configuration that focuses on complex artificial environments in general, and on cities and their dynamics, in particular. The specific experience gained at ESLab is employed in this paper to discuss the various theoretical, methodological, social and ethical issues associated with the above emerging bodies.Complex artificial environments - ESLab's experience
AbstractPortugali, J., Benenson, I., Omer, I., Fabrikant, R., Kasakin, H., Martens, K., Agmon, T., Birfur, S., Goldblatt, R., Hatna, E., Kharbash, V., Margalit, T., Munk-Vitelson, H., Nizry, G., Or, U., Porat, A., Roz, A., Talmor, K., & Winograd, M. (n.d.).Publication year
2006Page(s)
95-115AbstractThe Environmental Simulation Laboratory (ESLab) is one of several laboratories, research centers and planning and design organizations that have emerged in the last two decades with a configuration that focuses on complex artificial environments in general, and on cities and their dynamics, in particular. The specific experience gained at ESLab is employed in this paper to discuss the various theoretical, methodological, social and ethical issues associated with the above emerging bodies.Constructing cities, deconstructing scaling laws
AbstractArcaute, E., Hatna, E., Ferguson, P., Youn, H., Johansson, A., & Batty, M. (n.d.).Publication year
2015Journal title
Journal of the Royal Society InterfaceVolume
12Issue
102AbstractCities can be characterized and modelled through different urban measures. Consistency within these observables is crucial in order to advance towards a science of cities. Bettencourt et al. have proposed that many of these urban measures can be predicted through universal scaling laws. We develop a framework to consistently define cities, using commuting to work and population density thresholds, and construct thousands of realizations of systems of cities with different boundaries for England and Wales. These serve as a laboratory for the scaling analysis of a large set of urban indicators. The analysis shows that population size alone does not provide us enough information to describe or predict the state of a city as previously proposed, indicating that the expected scaling laws are not corroborated. We found that most urban indicators scale linearly with city size, regardless of the definition of the urban boundaries. However, when nonlinear correlations are present, the exponent fluctuates considerably.Coresidency of Immigrant Groups in a Diverse Inner-City Neighborhood of Whitechapel, London
AbstractFlint-Ashery, S., & Hatna, E. (n.d.).Publication year
2021Journal title
Housing Policy DebateAbstractA single family occupying one residential unit is the typical residential arrangement in cities of the Global North. However, specific communities tend to practice coresidency, wherein several families share the same residential unit. In this study, we evaluate immigrant groups’ coresidency tendencies in London’s East End Whitechapel neighborhood, through a door-to-door survey and interviews. We differentiate between horizontal and vertical family structures and find that a sizable percentage (44.4%) of the residential units were shared by two or more families. At the neighborhood level, we show that the segregated residential pattern of groups was correlated with the pattern of coresidency, indicating that the uneven spatial concentration of ethnic groups led to high densities of families in specific parts of Whitechapel. The interviews reveal that coresidency is not merely a result of economic constraints but also a residential preference reflecting the need for cohabitation with extended family members.Defining localities of inadequate treatment for childhood asthma : A GIS approach
AbstractPeled, R., Reuveni, H., Pliskin, J. S., Benenson, I., Hatna, E., & Tal, A. (n.d.).Publication year
2006Journal title
International Journal of Health GeographicsVolume
5AbstractBackground: The use of Geographic Information Systems (GIS) has great potential for the management of chronic disease and the analysis of clinical and administrative health care data. Asthma is a chronic disease associated with substantial morbidity, mortality, and health care use. Epidemiologic data from all over the world show an increasing prevalence of asthma morbidity and mortality despite the availability of effective treatment. These facts led to the emergence of strategies developed to improve the quality of asthma care. The objective: To develop an efficient tool for quality assurance and chronic disease management using a Geographic Information System (GIS). Geographic location: The southern region of Israel. January 1998 - Octo ber 2000. Databases: Administrative claims data of the largest HMO in Israel: drug dispensing registry, demographic data, Emergency Room visits, and hospitalization data bases. Methods: We created a list of six markers for inadequate pharmaceutical treatment of childhood asthma from the Israeli clinical guidelines. We used this list to search the drug dispensing registry to identify asthmatic children who received inadequate treatment and to assess their health care utilization and bad outcomes: emergency room visits and hospitalizations. Using GIS we created thematic maps on which we located the clinics with a high percentage of children for whom the treatment provided was not in adherence with the clinical guidelines. Results: 81 % of the children were found to have at least one marker for inadequate treatment; 17.5% were found to have more than one marker. Children with markers were found to have statistically significant higher rates of Emergency Room visits, hospitalizations and longer length of stay in hospital compared with children without markers. The maps show in a robust way which clinics provided treatment not in accord with the clinical guidelines. Those clinics have high rates of Emergency Room visits, hospitalizations and length of stay. Conclusion: Integration of clinical guidelines, administrative data and GIS can create an efficient interface between administrative and clinical information. This tool can be used for allocating sites for quality assurance interventions.Defining urban agglomerations to detect agglomeration economies
AbstractCottineau, C., Finance, O., Hatna, E., Arcaute, E., & Batty, M. (n.d.).Publication year
2016Journal title
arXivAbstractAgglomeration economies are a persistent subject of debate among economists and urban planners. Their definition turns on whether or not larger cities and regions are more efficient and more productive than smaller ones. We complement existing discussion on agglomeration economies and the urban wage premium here by providing a sensitivity analysis of estimated coefficients to different delineations of urban agglomeration as well as to different definitions of the economic measure that summarises the urban premium. This quantity can consist of total wages measured at the place of work, or of income registered at the place of residence. The chosen option influences the scaling behaviour of city size as well as the spatial distribution of the phenomenon at the city level. Spatial discrepancies between the distribution of jobs and the distribution of households at different economic levels makes city definitions crucial to the estimation of economic relations which vary with city size. We argue this point by regressing measures of income and wage over about five thousands different definitions of cities in France, based on our algorithmic aggregation of administrative spatial units at regular cutoffs which reflect density, population thresholds and commuting flows. We also go beyond aggregated observations of wages and income by searching for evidence of larger inequalities and economic segregation in the largest cities. This paper therefore considers the spatial and economic complexity of cities with respect to discussion about how we measure agglomeration economies. It provides a basis for reflection on alternative ways to model the processes which lead to observed variations, and this can provide insights for more comprehensive regional planning.Defining urban clusters to detect agglomeration economies
AbstractCottineau, C., Finance, O., Hatna, E., Arcaute, E., & Batty, M. (n.d.).Publication year
2019Journal title
Environment and Planning B: Urban Analytics and City ScienceVolume
46Issue
9Page(s)
1611-1626AbstractAgglomeration economies are a persistent subject of debate in regional science and city planning. Their definition turns on whether or not larger cities are more efficient than smaller ones. Here, we complement existing discussions on agglomeration economies by providing a sensitivity analysis of estimated externalities to the definitions of urban agglomeration. We regress wages versus population and jobs over thousands of different definitions of cities in France, based on an algorithmic aggregation of spatial units. We also search for evidence of larger inequalities in larger cities. This paper therefore focuses on the spatial and economic complexity of the mechanisms defining agglomeration within and between cities.Diverse cities or the systematic paradox of Urban Scaling Laws
AbstractCottineau, C., Hatna, E., Arcaute, E., & Batty, M. (n.d.).Publication year
2017Journal title
Computers, Environment and Urban SystemsVolume
63Page(s)
80-94AbstractScaling laws are powerful summaries of the variations of urban attributes with city size. However, the validity of their universal meaning for cities is hampered by the observation that different scaling regimes can be encountered for the same territory, time and attribute, depending on the criteria used to delineate cities. The aim of this paper is to present new insights concerning this variation, coupled with a sensitivity analysis of urban scaling in France, for several socio-economic and infrastructural attributes from data collected exhaustively at the local level. The sensitivity analysis considers different aggregations of local units for which data are given by the Population Census. We produce a large variety of definitions of cities (approximatively 5000) by aggregating local Census units corresponding to the systematic combination of three definitional criteria: density, commuting flows and population cutoffs. We then measure the magnitude of scaling estimations and their sensitivity to city definitions for several urban indicators, showing for example that simple population cutoffs impact dramatically on the results obtained for a given system and attribute. Variations are interpreted with respect to the meaning of the attributes (socio-economic descriptors as well as infrastructure) and the urban definitions used (understood as the combination of the three criteria). Because of the Modifiable Areal Unit Problem (MAUP) and of the heterogeneous morphologies and social landscapes in the cities' internal space, scaling estimations are subject to large variations, distorting many of the conclusions on which generative models are based. We conclude that examining scaling variations might be an opportunity to understand better the inner composition of cities with regard to their size, i.e. to link the scales of the city-system with the system of cities.Entity-based modeling of urban residential dynamics : The case of Yaffo, Tel Aviv
AbstractBenenson, I., Omer, I., & Hatna, E. (n.d.).Publication year
2002Journal title
Environment and Planning B: Planning and DesignVolume
29Issue
4Page(s)
491-512AbstractThe dynamics of the ethnic residential distribution in the Yaffo area of Tel Aviv, which is jointly occupied by Arab and Jewish residents, is simulated by means of an entity-based (EB) model. EB models consider householders as separate entities, whose residential behavior is defined by the properties of the surrounding infrastructure and of other householders. The power of the EB approach lies in its ability to interpret directly different forms of decisionmaker behavior in the model's terms. Several scenarios of residential interactions between members of local ethnic groups are compared on the basis of detailed georeferenced data taken from Israel's 1995 Population Census. The model simulates very closely the residential dynamics during the period 1955-95; the importance of the qualitative aspects of residential choice, as captured by the EB approach, is demonstrated by this correspondence.Ergodic properties of urban street networks in the UK
AbstractMasucci, A. P., Stanilov, K., Arcaute, E., Hatna, E., & Batty, M. (n.d.).Publication year
2013Page(s)
634-640AbstractIn this paper we study the statistical properties of urban street networks. We show that urban and non-urban street networks can be differentiated through their statistical properties, suggesting at a transition between two phases. We introduce a definition of city boundaries based on the percolation properties of the network in the street intersection density space, through the concept of city condensation threshold. Finally, using an historical dataset covering the growth of London during 224 years, we show that some global statistical measures display the same time and space evolution, i.e. they seem to be ergodic properties.Evidence for localization and urbanization economies in urban scaling
AbstractSarkar, S., Arcaute, E., Hatna, E., Alizadeh, T., Searle, G., & Batty, M. (n.d.).Publication year
2020Journal title
Royal Society Open ScienceVolume
7Issue
3AbstractWe study the scaling of (i) numbers of workers and aggregate incomes by occupational categories against city size, and (ii) total incomes against numbers of workers in different occupations, across the functional metropolitan areas of Australia and the USA. The number of workers and aggregate incomes in specific high-income knowledge economy-related occupations and industries show increasing returns to scale by city size, showing that localization economies within particular industries account for superlinear effects. However, when total urban area incomes and/or gross domestic products are regressed using a generalized Cobb-Douglas function against the number of workers in different occupations as labour inputs, constant returns to scale in productivity against city size are observed. This implies that the urbanization economies at the whole city level show linear scaling or constant returns to scale. Furthermore, industrial and occupational organizations, not population size, largely explain the observed productivity variable. The results show that some very specific industries and occupations contribute to the observed overall superlinearity. The findings suggest that it is not just size but also that it is the diversity of specific intra-city organization of economic and social activity and physical infrastructure that should be used to understand urban scaling behaviours.From schelling to spatially explicit modeling of urban ethnic and economic residential dynamics
AbstractBenenson, I., Hatna, E., & Or, E. (n.d.).Publication year
2009Journal title
Sociological Methods and ResearchVolume
37Issue
4Page(s)
463-497AbstractThe robustness of outcomes to the parameterization of behavioral rules is a crucial property of any model aimed at simulating complex human systems. Schelling model of residential segregation satisfies this criterion. Based on the recently available high-resolution census GIS, we apply Schelling model for investigating urban population patterns at the resolution of individual buildings and families. First, we simulate ethnic residential dynamics in Yaffo (an area of Tel Aviv), and demonstrate good quantitative correspondence for a 40-year period. Second, we investigate income-based residential patterns in nine Israeli cities, reveal their high heterogeneity, and explain the latter by the presence of low fraction of wealthier householders who are tolerant of their poorer neighbors and reside in their proximity. We extend Schelling model in this direction and demonstrate qualitative correspondence between the model's outcomes and the observed income-based residential patterns.