Urban Transport Expansions and Changes in the Spatial Structure of U.S. Cities: Implications for Productivity and Welfare

2020 ◽  
Vol 102 (5) ◽  
pp. 929-945 ◽  
Author(s):  
Nathaniel Baum-Snow
Keyword(s):  
Metropolitan Areas ◽  
Spatial Scales ◽  
Central City ◽  
Large Fraction ◽  
Agglomeration Economies ◽  
Urban Transport ◽  
Housing Cost ◽  
Housing Production ◽  
Factor Reallocation ◽  
Period Model

Each new radial highway serving large U.S. metropolitan areas decentralized 14% to 16% of central city working residents and 4% to 6% of jobs in the 1960–2000 period. Model calibrations yield implied elasticities of central city total factor productivity to central city employment relative to suburban employment of 0.04 to 0.09, meaning a large fraction of agglomeration economies operates at submetropolitan-area spatial scales. Each additional highway causes central city income net of commuting costs to increase by up to 2.4% and housing cost to decline by up to 1.3%. Factor reallocation toward land in housing production generates the plurality of the population decentralization caused by new highways.

Employment Decentralization in US Metropolitan Areas: Is Los Angeles an Outlier or the Norm?

1996 ◽  
Vol 28 (10) ◽  
pp. 1727-1743 ◽  
Author(s):  
P Gordon ◽  
H W Richardson
Keyword(s):  
Los Angeles ◽  
Metropolitan Areas ◽  
Central City ◽  
Service Industries ◽  
Similar Data ◽  
Metropolitan Statistical Areas ◽  
Common Process ◽  
Job Growth ◽  
Initial Movement ◽  
Labor Pools

In this paper data from the economic censuses are utilized to show that most job growth in the manufacturing, wholesaling, retail, and service industries in the 1982–87 period has been in the urban peripheries of the twelve consolidated metropolitan statistical areas (CMSAs). Similar data for 1976, 1980, and 1986 from another source, the Wharton Urban Decentralization Project, confirm many of these trends, and for a larger set of metropolitan areas. The results show that Los Angeles is more in the middle of the twelve CMSAs than it is an outlier. It is suggested that these common results reflect a common process, that is, an initial movement of households towards the metropolitan edge in search of amenities (or flight from central city ills), followed by the decentralization of firms to increase their access to suburban labor pools.

scholarly journals Testing Estimates of Housing Cost Differences among US Metropolitan Areas

2015 ◽  
Vol 2015 ◽  
pp. 1-13
Author(s):  
Todd Easton
Keyword(s):  
Census Data ◽  
Metropolitan Areas ◽  
Housing Cost ◽  
Cost Index ◽  
Housing Component ◽  
Fair Market ◽  
Cost Differences ◽  
Living Cost

This paper investigates the accuracy of six measures of housing cost differences among US metropolitan areas. Using Census data from 177 metropolitan areas, it tests the measures in two ways. First, it tests the ability of changes in the measures to predict changes in the shelter component of the metropolitan CPI from 1990 to 2000. Second, it tests the ability of the measures themselves to predict a proxy in 2000. A measure based on Fair Market Rents calculated by HUD placed second on the first test but did badly on the second. The housing component of the ACCRA index, a living cost measure frequently used by researchers, performed poorly on both tests. The top performer on both tests was a measure based on the average rent per room for a metropolitan area’s dwellings. Researchers wishing to control for living cost differences among places should consider including it in their living cost index.

scholarly journals Evidence of the Nonstationarity of the Terrestrial Bow Shock from Multi-Spacecraft Observations: Methodology, Results and Quantitative Comparison with PIC Simulations

2020 ◽  
Author(s):  
Christian Mazelle ◽  
Bertrand Lembege
Keyword(s):  
Magnetic Field ◽  
Lower Bound ◽  
Data Processing ◽  
Shock Front ◽  
Upper Bound ◽  
Spatial Scales ◽  
Large Fraction ◽  
Field Measurements ◽  
Bow Shock ◽  
Time Variability

Abstract. The nonstationarity of the terrestrial bow shock is analyzed in detail from in situ magnetic field measurements issued from the FGM experiment on board of Cluster mission. Attention is focused on statistical analysis of quasiperpendicular supercritical shock crossings. The present analysis stresses for the first time the importance of a careful and accurate methodology in the data processing which can be a source of confusion/misunderstanding if not treated properly. The analysis performed using 96 shock front crossings shows evidence of a strong variability of the microstructures of the shock front (foot and ramp) which are analyzed in deep details. Main results are: (i) most statistics clearly evidence that the ramp thickness is very narrow and can be as low as a few c/ωpe (electron inertia length), (ii) the width is narrower when the angle θBn (between the shock normal and the upstream magnetic field) approaches 90°, (iii) the foot thickness strongly varies but its variation has an upper limit provided by theoretical estimates given in previous studies (e.g., Schwartz et al., 1983; Gosling and Thomsen, 1985; Gosling and Robson, 1985); (iv) the presence of foot and overshoot, as shown in all front profiles confirms the importance of dissipative effects. Present results indicate that these features can be signatures of the shock front self-reformation among a few mechanisms of nonstationarity identified from numerical simulation/theoretical works. A comparison 2D PIC simulation for a perpendicular supercritical shock (used as reference), has been performed and it shows that: (a) the ramp thickness varies only slightly in time over a large fraction of the reformation cycle and reaches a lower bound value of the order of a few electron inertial length, (ii) in contrast, the foot width strongly varies during a self-reformation cycle but always stays lower than an upper bound value in agreement with the value given by Woods (1971), and (iii) as a consequence, the time variability of the whole shock front is depending on both ramp and foot variations. Moreover, a detailed comparative analysis shows that much elements of analysis were missing in previous reported works concerning both (i) the important criteria used in the data selection and (ii) the different and careful steps of the methodology used in the data processing itself. This absence of these precise elements of analysis makes the comparison with present work difficult, worse, it makes some final results and conclusive statements quite questionable at present time. A least, looking for a precise estimate of the shock transition thickness presents nowadays a restricted interest, since recent results show that the terrestrial shock is rather nonstationary and one unique typical spatial scaling of the microstructures of the front (ramp, foot) must be replaced by some variation ranges (with lower bound/upper bound values) within which the spatial scales of the fine structures can extend.

Identifying the Urban: Resident Perceptions of Community Character and Local Institutions in Eight Metropolitan Areas

2018 ◽  
Vol 17 (3) ◽  
pp. 858-882 ◽  
Author(s):  
Chase M. Billingham ◽  
Shelley McDonough Kimelberg
Keyword(s):  
Regression Models ◽  
Metropolitan Areas ◽  
Central City ◽  
The United States ◽  
Urban Resident ◽  
Local Institutions ◽  
Logistic Regression Models ◽  
Resident Perceptions ◽  
Local Schools ◽  
Using Data

What does the term “urban” signify as a descriptor of contemporary communities in the United States? We investigate this question using data from the Soul of the Community survey, examining how people within eight metropolitan areas characterize their communities. A substantial disjunction exists between where within their regions respondents live and how they describe those areas. Many central–city residents label their communities “suburban” or “rural,” while many outlying residents label their communities “urban.” We contend that people's experiences with important local institutions—specifically, local schools and the local public safety apparatus—shape their understanding of their communities. Logistic regression models support this contention. Controlling for where within their regions respondents live, they are more likely to label their communities “urban” if they perceive local schools to be low in quality and their neighborhoods to be unsafe. Notably, these effects are not consistent across racial and ethnic groups.

A Comparative Review of the Making of Urban Transport Policies in Metropolitan Areas in Southeast Asia

2014 ◽  
Vol 70 (4) ◽  
Author(s):  
Matthias Mueth ◽  
Anil Minhans
Keyword(s):  
Decision Making ◽  
Common Good ◽  
Metropolitan Areas ◽  
Urban Transport ◽  
Transport Systems ◽  
Technical Solution ◽  
Political Decision ◽  
Comparative Review ◽  
Policy Field ◽  
Political Decision Making

The urban transport systems are primarily the result of political decision-making processes, and only secondarily a matter of technical necessity or technical possibility, because every individual or group does have vested interests in transport policies, which are often conflicting if not inherently incompatible. What constitutes the so-called “common good” is not a technical question but ultimately a political one – while its implementation requires the suitable technical solution. This “comparative review of the making of urban transport policies in metropolitan areas of Singapore and Bangkok” analyses (1) the “input” of different actors into the political decision-making process, (2) how this input is processed by the various actors in government and administration, including the interaction of all participatory actors, and (3) finally how the results of these processes influence the form of the actual transport systems. The results are based on the research of the different polities influencing transport-related decisions in cities of Singapore and Bangkok. The process of decision-making is analysed using seven illustrative examples from these cities and the assessment of the transport systems is made according to pre-defined quantitative and qualitative data. This adopted approach is along the lines of classical policy-field analysis: In this study it examines the policy field of urban transport and draws conclusions, which are specific to the chosen cities and general to the policy field.

scholarly journals The socioecohydrology of rainwater harvesting in India: understanding water storage and release dynamics across spatial scales

2016 ◽  
Vol 20 (7) ◽  
pp. 2629-2647 ◽  
Author(s):  
Kimberly J. Van Meter ◽  
Michael Steiff ◽  
Daniel L. McLaughlin ◽  
Nandita B. Basu
Keyword(s):  
Rainwater Harvesting ◽  
Spatial Scales ◽  
Monsoon Season ◽  
Groundwater Resources ◽  
Large Fraction ◽  
Irrigated Agriculture ◽  
Small Scale ◽  
Northeast Monsoon ◽  
Crop Water ◽  
Tank Water

Abstract. Rainwater harvesting (RWH), the small-scale collection and storage of runoff for irrigated agriculture, is recognized as a sustainable strategy for ensuring food security, especially in monsoonal landscapes in the developing world. In south India, these strategies have been used for millennia to mitigate problems of water scarcity. However, in the past 100 years many traditional RWH systems have fallen into disrepair due to increasing dependence on groundwater. This dependence has contributed to accelerated decline in groundwater resources, which has in turn led to increased efforts at the state and national levels to revive older RWH systems. Critical to the success of such efforts is an improved understanding of how these ancient systems function in contemporary landscapes with extensive groundwater pumping and shifted climatic regimes. Knowledge is especially lacking regarding the water-exchange dynamics of these RWH tanks at tank and catchment scales, and how these exchanges regulate tank performance and catchment water balances. Here, we use fine-scale, water-level variation to quantify daily fluxes of groundwater, evapotranspiration (ET), and sluice outflows in four tanks over the 2013 northeast monsoon season in a tank cascade that covers a catchment area of 28 km2. At the tank scale, our results indicate that groundwater recharge and irrigation outflows comprise the largest fractions of the tank water budget, with ET accounting for only 13–22 % of the outflows. At the scale of the cascade, we observe a distinct spatial pattern in groundwater-exchange dynamics, with the frequency and magnitude of groundwater inflows increasing down the cascade of tanks. The significant magnitude of return flows along the tank cascade leads to the most downgradient tank in the cascade having an outflow-to-capacity ratio greater than 2. At the catchment scale, the presence of tanks in the landscape dramatically alters the catchment water balance, with runoff decreasing by nearly 75 %, and recharge increasing by more than 40 %. Finally, while water from the tanks directly satisfies  ∼ 40 % of the crop water requirement across the northeast monsoon season via surface water irrigation, a large fraction of the tank water is "wasted", and more efficient management of sluice outflows could lead to tanks meeting a higher fraction of crop water requirements.

scholarly journals Spatially-Resolved View of High-Redshift Starbursts: the case of Sub-mm Galaxies

2012 ◽  
Vol 8 (S295) ◽  
pp. 92-92
Author(s):  
Karín Menéndez-Delmestre ◽  
Andrew W. Blain ◽  
Mark Swinbank ◽  
Ian Smail ◽  
Rob J. Ivison ◽  
...  
Keyword(s):  
Star Formation ◽  
Adaptive Optics ◽  
Spatial Scales ◽  
Large Fraction ◽  
Spectroscopic Techniques ◽  
Infrared Galaxies ◽  
Star Forming ◽  
Luminous Infrared Galaxies ◽  
Disk Structure ◽  
Hα Emission

AbstractUltra-luminous infrared galaxies (LIR > 1012 L⊙) are locally rare, but appear to dominate the co-moving energy density at higher redshifts (z>2). Many of these are optically-faint, dust-obscured galaxies that have been identified by the detection of their thermal dust emission at sub-mm wavelengths. Multi-wavelength spectroscopic follow-up observations of these sub-mm galaxies (SMGs) have shown that they are massive (Mstellar ~ 1011 M⊙) objects undergoing intense star-formation (SFRs ~ 102−103 M⊙ yr−1) with a mean redshift of z ~ 2, coinciding with the epoch of peak quasar activity. The large fraction of AGNs in SMGs and the derived SMBH masses (M• < 108 M⊙) in these galaxies suggest that the submm phase may play an important role in the rapid growth of SMBHs. When both AGN and star-formation activity are present, long-slit spectroscopic techniques face difficulties in disentangling their contributions and may result in SFR and mass overestimates. We present an integral field view of the Hα emission in a sample of 3 SMGs at z~1.4–2.4 with the IFU instrument OSIRIS on Keck. Designed to be used with Laser Guide Star Adaptive Optics, OSIRIS allows a spatial resolution of up to 10× higher than what has been possible in previous seeing-limited studies of the ionized gas in these galaxies. Our main results are the following: (1) We detect multiple galactic-scale sub-components: the compact, broad Hα emission (FWHM >1000 km s−1) likely associated with an AGN, the more extended narrow-line Hα emission (FWHM ≲500 km s−1) of star-forming regions; the latter are dominated by multiple 1–2 kpc sized Hα-bright clumps, each contributing 1-25% of the total clump-integrated Hα emission. (2) We derive clump dynamical masses ~1–10×109M⊙, 1–2 orders of magnitude larger than the kpc-scaled stellar clumps uncovered in optically-selected z ~ 2 star-forming galaxies. (3) We determine high star-formation rate surface densities (ΣSFR~1–50 M⊙yr−1 kpc−2, after extinction correction), similar to local starbursts and luminous infrared galaxies. In contrast to these local environments, SMGs undergo such intense activity on significantly larger spatial scales as revealed by extended Hα emission over 4–16 kpc. (4) We find no evidence of ordered global motion as it would be found in a disk, but rather large velocity offsets (~ few × 100 km s−1) between the distinct stellar clumps. The merger interpretation is likely the most accurate scenario for the SMGs in our sample. However, the final test of whether an underlying disk structure is present will come from studies of the cold gas at the high spatial resolutions possible with ALMA.We refer the reader to Menéndez-Delmestre et al. (2012) for more details.

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