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2.
PLoS One ; 18(8): e0289826, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37561718

RESUMO

The digital economy may accelerate the upgrading of industrial structures and boost regional innovation output, effectively contributing to China's green economic transformation. The impact of the digital economy on developing the urban green economy is analyzed using data from 280 cities across China from 2010-2019. Using a fixed-effects model and the Spatial Durbin model, the digital economy is found to have a significant impact on urban green economy development. This result is shown to be robust to various factors. There is significant regional variability in the impact of the digital economy on green economic growth, with the strongest impact in the northeast, followed by the central and western regions. Meanwhile, non-resource-based cities and policy pilot cities have a more pronounced role in promoting the digital economy. The intermediate transmission chain of industrial structural upgrading and regional innovation output fosters the growth of the urban green economy via the digital economy. Regional innovation production is responsible for 30.848% of this growth, with the intermediate effect of industrial structural upgrading contributing to 38.155%.


Assuntos
Conservação de Recursos Energéticos , Tecnologia Digital , Desenvolvimento Econômico , Desenvolvimento Sustentável , China , Cidades/economia , Conservação de Recursos Energéticos/economia , Desenvolvimento Sustentável/economia , Tecnologia Digital/economia
3.
PLoS One ; 18(6): e0285173, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37379296

RESUMO

Based on the China City Commercial Credit Environment Index (CEI), a more scientific spatial DID model was used to examine the long-term impact of the opening of ports and trading in the late Qing Dynasty on the urban commercial credit environment, taking cities above the prefecture level in the Yangtze River Delta as a sample. The study confirms that: (1) the opening of ports and commerce in the late Qing Dynasty had a significant contribution to the urban commercial credit environment, which was conducive to the transformation of production methods and interpersonal relationships from traditional to modern, and to the improvement of the urban commercial credit environment. (2) Before the signing of the Treaty of Shimonoseki, the local forces of the late Qing Dynasty were resistant to the economic aggression of the Great Powers, and the positive impact of the opening of ports and trading on the commercial credit environment of port cities was more significant, but the impact was not obvious after the signing of the Treaty of Shimonoseki. (3) From the history of the opening of ports for trade in the late Qing Dynasty, the economic aggression of the Western powers against the non-patronage areas by means of the buying class objectively strengthened the concept of rule of law and credit awareness in the local market and exerted a long-term influence on the commercial credit environment of the cities, but the impact of the opening of ports for trade on the commercial credit environment of the patronage areas was not prominent. (4) Cities located in the sphere of influence of the common law powers had a more pronounced impact on the commercial credit environment as their institutions and concepts were more easily transplanted, while the impact of the opening of ports and trading on the commercial credit environment of cities in the sphere of influence of the civil law powers was not significant. Policy Insights: (1) Enhance the ability to negotiate with foreign countries on economic and trade matters from a level-headed world perspective, and be bold and adept at fighting unreasonable rules, standards and requirements in order to better optimise the business credit environment; (2) Regulate the use of administrative resources and avoid undue administrative intervention, which is an important prerequisite for improving the basic system of the market economy to enhance the business credit environment; (3) Emphasise both connotative development to follow a Chinese style modernisation path, and (3) emphasising selective cooperation to promote outward development, promoting the interaction, convergence and matching of domestic and foreign regulations, and continuously improving the regional commercial credit environment.


Assuntos
Cidades , Comércio , China , Cidades/economia , Comércio/economia , Comércio/história , História do Século XIX , História do Século XX , Rios
4.
Environ Sci Pollut Res Int ; 30(29): 74166-74185, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37204575

RESUMO

As a new economic form, the digital economy is not only empowering new impetus to economic growth, but also reshaping specific business forms of economical operation. Therefore, we conducted an empirical test to verify the impact and mechanism of pollution reduction in the digital economy, based on the panel data of 280 prefecture-level cities in China from 2011 to 2019. The results show that, first the development of the digital economy indeed has the positive effect of realizing pollution reduction. The results of mediating effect test indicate the influence mechanism mainly rely on promoting the upgrading of industrial structure (structural effect) and upgrading the level of green technology innovation (technical effect). Second, the results of regional heterogeneity analysis show that the emission reduction effect of digital economy development on four pollutants is characterized by weakness in the east and strong in the west in regional distribution. Third, the development of digital economy has a threshold effect on the level of economic development to achieve its pollution reduction effect. Further identification of the threshold effect indicates that the higher the level of economic development, the better in emission reduction effect.


Assuntos
Tecnologia Digital , Desenvolvimento Econômico , Poluição Ambiental , Desenvolvimento Sustentável , China , Cidades/economia , Tecnologia Digital/economia , Poluentes Ambientais , Poluição Ambiental/economia , Poluição Ambiental/prevenção & controle , Desenvolvimento Sustentável/economia
5.
PLoS One ; 17(3): e0263796, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35271570

RESUMO

As an important financial means for governments to improve the quality of economic development, government debt greatly affects the quality of local environmental governance. Based on a theoretical mechanism analysis that uses the pollutant emissions panel data and new caliber urban investment bond data of 273 cities in China, this paper empirically tests the impact of local government debt on urban emission reduction and the mechanism that drives this impact. We find that local government debt significantly promotes urban emissions reduction, and as urban pollution becomes more aggravated, this promoting effect has a dynamic path, first strengthening and then weakening. The role of local government debt in promoting urban emission reduction is characterized by both temporal and spatial heterogeneity. A mechanistic analysis shows that local government debt can promote urban emission reduction by promoting urban environmental innovation, with green invention patents demonstrating a stronger intermediary role than green utility model patents.


Assuntos
Poluição Ambiental/economia , Governo Local , Poluição do Ar/análise , Poluição do Ar/economia , Poluição do Ar/prevenção & controle , China , Cidades/economia , Conservação dos Recursos Naturais , Desenvolvimento Econômico , Política Ambiental , Poluição Ambiental/análise , Poluição Ambiental/prevenção & controle
6.
PLoS One ; 17(2): e0263577, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35143557

RESUMO

Geographic accessibility plays a key role in health care inequality but remains insufficiently investigated in China, primarily due to the lack of accurate, broad-coverage data on supply and demand. In this paper, we employ an innovative approach to local supply-and-demand conditions to (1) reveal the status quo of the distribution of health care provision and (2) examine whether individual households from communities with different housing prices can acquire equal and adequate quality health care services within and across 361 cities in China. Our findings support previous conclusions that quality hospitals are concentrated in cities with high administrative rankings and developmental levels. However, after accounting for the population size an "accessible" hospital serves, we discern "pro-poor" inequality in accessibility to care (denoted as GAPSD) and that GAPSD decreases along with increases in administrative rankings of cities and in community ratings. This paper is significant for both research and policy-making. Our approach successfully reveals an "unexpected" pattern of health care inequality that has not been reported before, and our findings provide a nationwide, detailed benchmark that facilitates the assessment of health and urban policies, as well as associated policy-making.


Assuntos
Serviços de Saúde/economia , Disparidades em Assistência à Saúde/economia , Big Data , China , Cidades/economia , Serviços de Saúde Comunitária/economia , Humanos , Pobreza
7.
PLoS One ; 16(10): e0254582, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34710085

RESUMO

To build better theories of cities, companies, and other social institutions such as universities, requires that we understand the tradeoffs and complementarities that exist between their core functions, and that we understand bounds to their growth. Scaling theory has been a powerful tool for addressing such questions in diverse physical, biological and urban systems, revealing systematic quantitative regularities between size and function. Here we apply scaling theory to the social sciences, taking a synoptic view of an entire class of institutions. The United States higher education system serves as an ideal case study, since it includes over 5,800 institutions with shared broad objectives, but ranges in strategy from vocational training to the production of novel research, contains public, nonprofit and for-profit models, and spans sizes from 10 to roughly 100,000 enrolled students. We show that, like organisms, ecosystems and cities, universities and colleges scale in a surprisingly systematic fashion following simple power-law behavior. Comparing seven commonly accepted sectors of higher education organizations, we find distinct regimes of scaling between a school's total enrollment and its expenditures, revenues, graduation rates and economic added value. Our results quantify how each sector leverages specific economies of scale to address distinct priorities. Taken together, the scaling of features within a sector along with the shifts in scaling across sectors implies that there are generic mechanisms and constraints shared by all sectors, which lead to tradeoffs between their different societal functions and roles. We highlight the strong complementarity between public and private research universities, and community and state colleges, that all display superlinear returns to scale. In contrast to the scaling of biological systems, our results highlight that much of the observed scaling behavior is modulated by the particular strategies of organizations rather than an immutable set of constraints.


Assuntos
Universidades/economia , Cidades/economia , Ecossistema , Humanos , Organizações/economia
8.
Dig Dis Sci ; 66(11): 3635-3658, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34518939

RESUMO

AIM: To report revolutionary reorganization of academic gastroenterology division from COVID-19 pandemic surge at metropolitan Detroit epicenter from 0 infected patients on March 9, 2020, to > 300 infected patients in hospital census in April 2020 and > 200 infected patients in April 2021. SETTING: GI Division, William Beaumont Hospital, Royal Oak, has 36 GI clinical faculty; performs > 23,000 endoscopies annually; fully accredited GI fellowship since 1973; employs > 400 house staff annually since 1995; tertiary academic hospital; predominantly voluntary attendings; and primary teaching hospital, Oakland-University-Medical-School. METHODS: This was a prospective study. Expert opinion. Personal experience includes Hospital GI chief > 14 years until 2020; GI fellowship program director, several hospitals > 20 years; author of > 300 publications in peer-reviewed GI journals; committee-member, Food-and-Drug-Administration-GI-Advisory Committee > 5 years; and key hospital/medical school committee memberships. Computerized PubMed literature review was performed on hospital changes and pandemic. Study was exempted/approved by Hospital IRB, April 14, 2020. RESULTS: Division reorganized patient care to add clinical capacity and minimize risks to staff of contracting COVID-19 infection. Affiliated medical school changes included: changing "live" to virtual lectures; canceling medical student GI electives; exempting medical students from treating COVID-19-infected patients; and graduating medical students on time despite partly missing clinical electives. Division was reorganized by changing "live" GI lectures to virtual lectures; four GI fellows temporarily reassigned as medical attendings supervising COVID-19-infected patients; temporarily mandated intubation of COVID-19-infected patients for esophagogastroduodenoscopy; postponing elective GI endoscopies; and reducing average number of endoscopies from 100 to 4 per weekday during pandemic peak! GI clinic visits reduced by half (postponing non-urgent visits), and physical visits replaced by virtual visits. Economic pandemic impact included temporary, hospital deficit subsequently relieved by federal grants; hospital employee terminations/furloughs; and severe temporary decline in GI practitioner's income during surge. Hospital temporarily enhanced security and gradually ameliorated facemask shortage. GI program director contacted GI fellows twice weekly to ameliorate pandemic-induced stress. Divisional parties held virtually. GI fellowship applicants interviewed virtually. Graduate medical education changes included weekly committee meetings to monitor pandemic-induced changes; program managers working from home; canceling ACGME annual fellowship survey, changing ACGME physical to virtual site visits; and changing national conventions from physical to virtual. CONCLUSION: Reports profound and pervasive GI divisional changes to maximize clinical resources devoted to COVID-19-infected patients and minimize risks of transmitting infection.


Assuntos
COVID-19/economia , COVID-19/epidemiologia , Economia Hospitalar/organização & administração , Gastroenterologia/educação , Administração Hospitalar/métodos , SARS-CoV-2 , Cidades/economia , Cidades/epidemiologia , Educação de Pós-Graduação em Medicina/organização & administração , Gastroenterologia/economia , Administração Hospitalar/economia , Humanos , Internato e Residência , Michigan/epidemiologia , Afiliação Institucional/economia , Afiliação Institucional/organização & administração , Estudos Prospectivos , Faculdades de Medicina/organização & administração
9.
PLoS One ; 16(8): e0256334, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34407117

RESUMO

Natural resources are scarce in the Loess Plateau, and the ecological environment is fragile. Sustainable development requires special attention to resource and environmental carrying capacity (RECC). This study selected 24 representative cities in five natural areas of the Loess Plateau; used the entropy-weight-based TOPSIS method to evaluate and analyze the RECC of each city and region from 2013 to 2018; established a diagnosis model to identify the obstacle factors restricting the improvement of RECC; and constructed the theoretical framework of the RECC system mechanism. The results show that the RECC of the Loess Plateau is increasing in general but is relatively small. The environmental and social subsystems have the highest and lowest carrying capacities, respectively. There is an evident contradiction between economic development and the environment. Population density, investment in technological innovation, per capita sown area, and per capita water resources are the main obstacles affecting the improvement of RECC in the Loess Plateau. Such evaluations and diagnoses can support ecological civilization and sustainable development.


Assuntos
Conservação dos Recursos Hídricos/tendências , Desenvolvimento Econômico/tendências , Desenvolvimento Sustentável/economia , China , Cidades/economia , Ecossistema , Entropia , Humanos
10.
PLoS One ; 16(6): e0252127, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34161328

RESUMO

Globally, the influx of refugee, migrant, and immigrant populations into small centers of industrialized agriculture has called attention to a looming public health crisis. As small towns shift from remote villages into rural, agri-industrial centers, they offer limited access to amenities needed to support human well-being. Our study focused on three Iowa towns that continue to experience an increase in under-represented minority populations and decline of majority populations as a proxy for studying shifting populations in an era of industrialized agriculture and global capital. We aimed to understand the socioecological impact of built environments-outdoor locations where people live and work-and likelihood of environmental exposures to impact vulnerable populations. Urban socioecological measures tend to present contradictory results in small towns due to their reliance on density and proximity. To compensate, we used post-occupancy evaluations (POE) to examine built environments for evidence of access to environmental design criteria to support healthy behaviors. The study systematically identified 44 locations on transects across three small towns to employ a 62 item POE and assess multiple environmental criteria to crosscut design with environmental health disparities. Principal-components factor analysis identified two distinct significant components for environmental risk and population vulnerability, supporting similar studies on parallel communities. Multilevel modeling found a divergence between supportive environmental design coupled with an increase environmental risk due to location. The combined effect likely contributes to environmental health disparities. The study provides a strategy for auditing small town built environments as well as insight into achieving equity.


Assuntos
Exposição Ambiental/economia , Saúde Ambiental/educação , Saúde Pública/economia , Agricultura/economia , Cidades/economia , Humanos , Iowa , População Rural
12.
Proc Natl Acad Sci U S A ; 118(20)2021 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-33972421

RESUMO

We propose a dedicated research effort on the determinants of settlement persistence in the ancient world, with the potential to significantly advance the scientific understanding of urban sustainability today. Settlements (cities, towns, villages) are locations with two key attributes: They frame human interactions and activities in space, and they are where people dwell or live. Sustainability, in this case, focuses on the capacity of structures and functions of a settlement system (geography, demography, institutions) to provide for continuity of safe habitation. The 7,000-y-old experience of urbanism, as revealed by archaeology and history, includes many instances of settlements and settlement systems enduring, adapting to, or generating environmental, institutional, and technological changes. The field of urban sustainability lacks a firm scientific foundation for understanding the long durée, relying instead on narratives of collapse informed by limited case studies. We argue for the development of a new interdisciplinary research effort to establish scientific understanding of settlement and settlement system persistence. Such an effort would build upon the many fields that study human settlements to develop new theories and databases from the extensive documentation of ancient and premodern urban systems. A scientific foundation will generate novel insights to advance the field of urban sustainability.


Assuntos
Emigração e Imigração/estatística & dados numéricos , Dinâmica Populacional/estatística & dados numéricos , Crescimento Sustentável , População Urbana/estatística & dados numéricos , Urbanização , Agricultura/métodos , Agricultura/tendências , Arqueologia/estatística & dados numéricos , Cidades/classificação , Cidades/economia , Emigração e Imigração/tendências , Meio Ambiente , Geografia , Humanos , Modelos Teóricos , Dinâmica Populacional/tendências , Fatores Socioeconômicos , População Urbana/tendências , Reforma Urbana/métodos , Reforma Urbana/estatística & dados numéricos , Reforma Urbana/tendências
13.
PLoS One ; 16(4): e0250375, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33886666

RESUMO

This study aims to explore the freight demand network spatial patterns in six provinces of central China from the perspective of the spread of the epidemic and the freight imbalance and breakout. To achieve this purpose, the big data of "cart search" demand information provided by small and medium freight enterprises on the freight information platform are analyzed. 343,690 pieces of freight demand big data on the freight information platform and Python, ArcGIS, UCINET, and Gephi software are used. The results show that: (1) The choke-point of unbalanced freight demand network is Wuhan, and the secondary choke-points are Hefei and Zhengzhou. (2) In southern China, a chain reaction circle of freight imbalance is formed with Wuhan, Hefei, and Nanchang as the centers. In northern China, a chain reaction circle of freight imbalance is formed with Zhengzhou and Taiyuan as the centers. (3) The freight demand of the six provinces in central China exhibits typical characteristics of long tail distribution with large span and unbalanced distribution. (4) The import and export of freight in different cities vary greatly, and the distribution is unbalanced. This study indicates the imbalance difference, chain reaction, keys and hidden troubles posed by the freight demand network. From the perspectives of freight transfer breakout, freight balance breakout, freight strength breakout, and breakout of freight periphery cities, we propose solutions to breakouts in the freight market in six provinces of central China in the post-epidemic era.


Assuntos
COVID-19/economia , COVID-19/epidemiologia , Recessão Econômica , Epidemias/economia , SARS-CoV-2 , COVID-19/virologia , China/epidemiologia , Cidades/economia , Cidades/epidemiologia , Humanos , Software , Análise Espacial
14.
PLoS One ; 16(4): e0250398, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33857262

RESUMO

Ethnic and gendered employment gaps are mainly explained by individual characteristics, while less attention is paid to occupational structures. Drawing on administrative data, this article analyses the impact of occupational characteristics on top of individual attributes in the urban labour market of Vienna. Both set of variables can explain observed employment gaps to a large extent, but persistent gaps remain, in particular among females. The article's main finding is that the occupational structure appears to have gendered effects. While men tend to benefit from ethnic segregation, women face difficulties when looking for jobs with high shares of immigrant workers. Looking for jobs in occupations that recruit from relatively few educational backgrounds (credentials) is beneficial for both sexes at the outset unemployment, but among females this competitive advantage diminishes over time. The article concludes by discussing potential strategies to avoid the traps of occupational segregation.


Assuntos
Emigrantes e Imigrantes/estatística & dados numéricos , Emprego/tendências , Etnicidade/estatística & dados numéricos , Ocupações/tendências , Salários e Benefícios/tendências , Adolescente , Adulto , Áustria , Cidades/economia , Escolaridade , Feminino , Humanos , Acontecimentos que Mudam a Vida , Masculino , Pessoa de Meia-Idade , Ocupações/economia , Ocupações/ética , Classe Social , Previdência Social/estatística & dados numéricos , População Urbana/tendências
15.
PLoS One ; 16(4): e0250204, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33901224

RESUMO

Understanding the dynamics by which urban areas attract visitors is important in today's cities that are continuously increasing in population towards higher densities. Identifying services that relate to highly attractive districts is useful to make policies regarding the placement of such places. Thus, we present a framework for classifying districts in cities by their attractiveness to daily commuters and relating Points of Interests (POIs) types to districts' attraction patterns. We used Origin-Destination matrices (ODs) mined from cell phone data that capture the flow of trips between each pair of places in Riyadh, Saudi Arabia. We define the attraction profile for a place based on three main statistical features: The number of visitors a place received, the distribution of distance traveled by visitors on the road network, and the spatial spread of locations from where trips started. We used a hierarchical clustering algorithm to classify all places in the city by their features of attraction. We discovered three main types of Urban Attractors in Riyadh during the morning period: Global, which are significant places in the city, Downtown, which contains the central business district, and Residential attractors. In addition, we uncovered what makes districts possess certain attraction patterns. We used a statistical significance testing approach to quantify the relationship between Points of Interests (POIs) types (services) and the patterns of Urban Attractors detected.


Assuntos
Dinâmica Populacional/tendências , População Urbana/tendências , Algoritmos , Cidades/economia , Cidades/estatística & dados numéricos , Análise por Conglomerados , Comércio , Humanos , Modelos Teóricos , Arábia Saudita , Meios de Transporte , Viagem
16.
PLoS One ; 16(4): e0249715, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33909628

RESUMO

Urban tree cover provides benefits to human health and well-being, but previous studies suggest that tree cover is often inequitably distributed. Here, we use National Agriculture Imagery Program digital ortho photographs to survey the tree cover inequality for Census blocks in US large urbanized areas, home to 167 million people across 5,723 municipalities and other Census-designated places. We compared tree cover to summer land surface temperature, as measured using Landsat imagery. In 92% of the urbanized areas surveyed, low-income blocks have less tree cover than high-income blocks. On average, low-income blocks have 15.2% less tree cover and are 1.5°C hotter than high-income blocks. The greatest difference between low- and high-income blocks was found in urbanized areas in the Northeast of the United States, where low-income blocks in some urbanized areas have 30% less tree cover and are 4.0°C hotter. Even after controlling for population density and built-up intensity, the positive association between income and tree cover is significant, as is the positive association between proportion non-Hispanic white and tree cover. We estimate, after controlling for population density, that low-income blocks have 62 million fewer trees than high-income blocks, equal to a compensatory value of $56 billion ($1,349/person). An investment in tree planting and natural regeneration of $17.6 billion would be needed to close the tree cover disparity, benefitting 42 million people in low-income blocks.


Assuntos
Conservação dos Recursos Naturais/estatística & dados numéricos , Renda/estatística & dados numéricos , Características de Residência/estatística & dados numéricos , Árvores/crescimento & desenvolvimento , Cidades/economia , Cidades/estatística & dados numéricos , Demografia/classificação , Demografia/economia , Demografia/estatística & dados numéricos , Humanos , Densidade Demográfica , Temperatura , Estados Unidos , Urbanização
18.
PLoS One ; 16(3): e0247609, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33684163

RESUMO

Entrepreneurship activity varies significantly across cities. We use the novel data for 1,652 ecosystem actors across sixteen cities in nine developing and transition economies during 2018-2019 to examine the role that institutional context plays in facilitating the productive entrepreneurship and reducing the unproductive entrepreneurship. This study is the first to develop and test a model of multi-dimensional institutional arrangements in cities. It demonstrates that not just that institutions matter in shaping the entrepreneurship ecosystem in cities, but in particular those institutional arrangements enhancing the productive and reducing unproductive entrepreneurship. Our findings suggest that differences between normative, cognitive, and regulatory pillars are associated with variance in both types of entrepreneurship in cities. For the formation of productive and high-growth entrepreneurs, all three pillars of institutional arrangement matter. For unproductive entrepreneurship normative pillar of institutions and the role of civil society matter most. This study has theoretical and practical implications for entrepreneurship ecosystem policy in cities.


Assuntos
Economia/estatística & dados numéricos , Empreendedorismo/organização & administração , Invenções/tendências , Modelos Econométricos , Cidades/economia , Países em Desenvolvimento , Eficiência , Empreendedorismo/legislação & jurisprudência , Regulamentação Governamental , Humanos , Invenções/economia
19.
PLoS One ; 16(2): e0245011, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33596219

RESUMO

We analyze the trade-offs between health and the economy during the period of social distancing in São Paulo, the state hardest hit by the COVID-19 pandemic in Brazil. We use longitudinal data with municipal-level information and check the robustness of our estimates to several sources of bias, including spatial dependence, reverse causality, and time-variant omitted variables. We use exogenous climate shocks as instruments for social distancing since people are more likely to stay home in wetter and colder periods. Our findings suggest that the health benefits of social distancing differ by levels of municipal development and may have vanished if the COVID-19 spread was not controlled in neighboring municipalities. In turn, we did not find evidence that municipalities with tougher social distancing performed worse economically. Our results also highlight that estimates that do not account for endogeneity may largely underestimate the benefits of social distancing on reducing the spread of COVID-19.


Assuntos
COVID-19/economia , COVID-19/psicologia , Quarentena/economia , Brasil/epidemiologia , COVID-19/epidemiologia , COVID-19/prevenção & controle , Cidades/economia , Cidades/epidemiologia , Humanos , Pandemias/economia , Pandemias/prevenção & controle , Distanciamento Físico , Quarentena/psicologia , SARS-CoV-2/isolamento & purificação
20.
PLoS One ; 16(1): e0245771, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33481927

RESUMO

Urban scaling and Zipf's law are two fundamental paradigms for the science of cities. These laws have mostly been investigated independently and are often perceived as disassociated matters. Here we present a large scale investigation about the connection between these two laws using population and GDP data from almost five thousand consistently-defined cities in 96 countries. We empirically demonstrate that both laws are tied to each other and derive an expression relating the urban scaling and Zipf exponents. This expression captures the average tendency of the empirical relation between both exponents, and simulations yield very similar results to the real data after accounting for random variations. We find that while the vast majority of countries exhibit increasing returns to scale of urban GDP, this effect is less pronounced in countries with fewer small cities and more metropolises (small Zipf exponent) than in countries with a more uneven number of small and large cities (large Zipf exponent). Our research puts forward the idea that urban scaling does not solely emerge from intra-city processes, as population distribution and scaling of urban GDP are correlated to each other.


Assuntos
Cidades , Densidade Demográfica , Cidades/economia , Modelos Estatísticos
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