Economic Impact of the James River Park System

The James River Park System (JRPS), “a Little Bit of Wilderness in the Heart of the City,” is a unique part of Richmond’s Department of Parks, Recreation and Community Facilities. With 550 acres of shoreline and islands in the capital of the Commonwealth of Virginia, the JRPS extends in 14 sections from the Huguenot Bridge (West) to a half mile beyond the I-95 Bridge (East). It includes most of the fall line of the James River, and features rocks, rapids, meadows, and forests that make for an area of unspoiled natural beauty. Large cities around the United States routinely engage researchers to examine the economic value of their Park Systems. These efforts generally assess seven core criteria including (1) property values, (2) revenue associated with tourism, (3) direct use, (4) health, (5) community cohesion, (6) clean water and (7) clean air. This study, the first of its kind for the JRPS, was conducted between November 2016 and March 2017. Due to the tight timeframe, the authors examined only a subset of these factors: property values and tourism. They offer evidence of the value – to all Richmond citizens and to the City – of JRPS’ natural areas, attracting more visitors than any other Metro Richmond destinations

Finite State Markov-Chain Approximations to Highly Persistent Processes

This paper re-examines the Rouwenhorst method of approximating first-order autoregressive processes. This method is appealing because it can match the conditional and unconditional mean, the conditional and unconditional variance and the first-order autocorrelation of any AR(1) process. This paper provides the first formal proof of this and other results. When comparing to five other methods, the Rouwenhorst method has the best performance in approximating the business cycle moments generated by the stochastic growth model. In addition, when the Rouwenhorst method is used, moments computed directly off the stationary distribution are as accurate as those obtained using Monte Carlo simulations.Numerical Methods; Finite State Approximations; Optimal Growth Model

A Quantitative Analysis of Suburbanization and the Diffusion of the Automobile

Suburbanization in the U.S. between 1910 and 1970 was concurrent with the rapid diffusion of the automobile. A circular city model is developed in order to access quantitatively the contribution of automobiles and rising incomes to suburbanization. The model incorporates a number of driving forces of suburbanization and car adoption, including falling automobile prices, rising real incomes, changing costs of traveling by car and with public transportation, and urban population growth. According to the model, 60 percent of postwar (1940-1970) suburbanization can be explained by these factors. Rising real incomes and falling automobile prices are shown to be the key drivers of suburbanization.automobile; suburbanization; population density gradients; technological progress

Finite State Markov-Chain Approximations to Highly Persistent Processes

This paper re-examines the Rouwenhorst method of approximating first-order autoregressive processes. This method is appealing because it can match the conditional and unconditional mean, the conditional and unconditional variance and the first-order autocorrelation of any AR(1) process. This paper provides the first formal proof of this and other results. When comparing to five other methods, the Rouwenhorst method has the best performance in approximating the business cycle moments generated by the stochastic growth model. It is shown that, equipped with the Rouwenhorst method, an alternative approach to generating these moments has a higher degree of accuracy than the simulation method.Numerical Methods, Finite State Approximations, Optimal Growth Model

Suburbanization and the Automobile

During the period 1910 to 1970, an increasing fraction of the urban population in the US chose to live on the outskirts of central cities. This was also a time when a major innovation in transportation technology, the automobile, was introduced and widely adopted. The objective of this paper is to assess quantitatively the relationship between the two. To achieve this, a simple model is constructed in which agents can choose where to live and whether or not to buy a car. When the model is calibrated, it can explain about 70 percent of the rise in car-ownership over the period 1910 to 1970 and all of the suburbanization trend. According to the model, rising income and falling car prices alone are not enough to generate the suburbanization trend. It is essential to have also: (i) a declining cost of commuting by car which allows car-owners to live further away from the city center, and (ii) a rising cost of using public transportation which encourages agents to make the swith to automobiles.automobiles, suburbanization, population density gradients

A Quantitative Analysis of Suburbanization and the Diffusion of the Automobile

Suburbanization in the U.S. between 1910 and 1970 was concurrent with the rapid diffusion of the automobile. A circular city model is developed in order to access quantitatively the contribution of automobiles and rising incomes to suburbanization. The model incorporates a number of driving forces of suburbanization and car adoption, including falling automobile prices, rising real incomes, changing costs of traveling by car and with public transportation, and urban population growth. According to the model, 60 percent of postwar (1940-1970) suburbanization can be explained by these factors. Rising real incomes and falling automobile prices are shown to be the key drivers of suburbanization.automobile; suburbanization; population density gradients; technological progress

Finite State Markov-Chain Approximations to Highly Persistent Processes

This paper re-examines the Rouwenhorst method of approximating first-order autoregressive processes. This method is appealing because it can match the conditional and unconditional mean, the conditional and unconditional variance and the first-order autocorrelation of any AR(1) process. This paper provides the first formal proof of this and other results. When comparing to five other methods, the Rouwenhorst method has the best performance in approximating the business cycle moments generated by the stochastic growth model. It is shown that, equipped with the Rouwenhorst method, an alternative approach to generating these moments has a higher degree of accuracy than the simulation method.Numerical Methods; Finite State Approximations; Optimal Growth Model

Magnetic-Field-Induced Hybridization of Electron Subbands in a Coupled Double Quantum Well

We employ a magnetocapacitance technique to study the spectrum of the soft two-subband (or double-layer) electron system in a parabolic quantum well with a narrow tunnel barrier in the centre. In this system unbalanced by gate depletion, at temperatures T\agt 30 mK we observe two sets of quantum oscillations: one originates from the upper electron subband in the closer-to-the-gate part of the well and the other indicates the existence of common gaps in the spectrum at integer fillings. For the lowest filling factors $\nu=1$ and $\nu=2$, both the common gap presence down to the point of one- to two-subband transition and their non-trivial magnetic field dependences point to magnetic-field-induced hybridization of electron subbands.Comment: Major changes, added one more figure, the latest version to be published in JETP Let

The Shapiro Conjecture: Prompt or Delayed Collapse in the head-on collision of neutron stars?

We study the question of prompt vs. delayed collapse in the head-on collision of two neutron stars. We show that the prompt formation of a black hole is possible, contrary to a conjecture of Shapiro which claims that collapse is delayed until after neutrino cooling. We discuss the insight provided by Shapiro's conjecture and its limitation. An understanding of the limitation of the conjecture is provided in terms of the many time scales involved in the problem. General relativistic simulations in the Einstein theory with the full set of Einstein equations coupled to the general relativistic hydrodynamic equations are carried out in our study.Comment: 4 pages, 7 figure