Stochastic capital depreciation and the comovement of hours and productivity

An unresolved question concerning stochastic depreciation shocks is whether they have to be unrealistically large to have any useful role in a dynamic general equilibrium model economy, as Ambler and Paquet (1994) first suggested. We first consider implied depreciation rates from sectoral data from the Bureau of Economic Analysis. These depreciation rates vary across time solely due to compositional changes within each sector. Hence, they tend to understate the range of fluctuation that would hold if the economic shelf life of capital varied endogenously as in Cooley, Greenwood and Yorukoglu (1997). We find, however, that if depreciation rates follow a Markov switching process, a low variance of the depreciation rate can generate the low correlation between hours worked and productivity in a simple model economy. White noise and autoregressive depreciation shocks, in contrast, require a counterfactually large variance in the depreciation rate to reduce the hours-productivity correlation. We also illustrate the level effects implied by nonlinear decision rules in simulations of dynamic general equilibrium models that include Markov switching parameters. Linear decision rules, in contrast, imply certainty equivalence and ignore the aversion that agents have to the skewed shock distributions that characterize Markov switching.Econometric models ; Productivity

Speed Limits in General Relativity

Some standard results on the initial value problem of general relativity in matter are reviewed. These results are applied first to show that in a well defined sense, finite perturbations in the gravitational field travel no faster than light, and second to show that it is impossible to construct a warp drive as considered by Alcubierre (1994) in the absence of exotic matter.Comment: 7 pages; AMS-LaTeX; accepted for publication by Classical and Quantum Gravit

Merging Ahead, Increase Speed: A Pilot of Funder-Driven Nonprofit Restructuring

Nonprofit agencies face increasing competition for scarce funding resources. Many agencies are considering ways to restructure themselves, often via mergers and acquisitions, as a way to become more effective and competitive. This case study examines a pilot initiative in Cleveland, Ohio, in which philanthropic funders invited and supported nonprofits in the pursuit of significant restructuring efforts. Health and human service nonprofits were recruited into a three-phase facilitated pilot that assisted the agency executive directors and boards in determining what type of restructuring was feasible and desirable. Overall, 75 nonprofits participated in some part of the pilot, 17 of which formally explored a restructuring opportunity within the pilot year, and eight of which ultimately consolidated. The study highlights key learnings from the initiative and the implications for the nonprofit sector in the promotion of restructuring discussions

Teaching Spatial Data Analysis: A Case Study with Recommendations

Learning from data is a valuable skill for nonprofit professionals and researchers. Often, data have a spatial component, and data relevant to the nonprofit sector are no exception. Understanding spatial aspects of the nonprofit sector may provide immense value to social entrepreneurs, funders, and policy makers, by guiding programmatic decisions, facilitating resource allocation, and development policy. As a result, spatial thinking has become an essential component of critical thinking and decision making among nonprofit professionals. The goal of this case study is to support and encourage instruction of spatial data analysis and spatial thinking in nonprofit studies. The case study presents a local nonprofit data set, along with open data and code, to assist the instructors teaching spatial aspects of the nonprofit sector. Pedagogical approaches are discussed

Exploring Niche Alteration in Nonprofit Organizations

The organizational niche is a concept integral to organizational ecology, reflecting an organization’s mission, expertise, capacity, and resource requirements. The choice of niche is crucial to the viability of the organization; however, the reasons organizations alter their niche are poorly understood. We hypothesize that nonprofit organizations alter their niche to reduce environmental pressure and gain access to resources. The results indicate that niche alteration predicts increases in total revenue with average increases in revenue from program services and contributions (depending on the measure). Additionally, nonprofits that are younger, larger, and have more concentrated revenue, are more likely to alter their niche

Taking it to Scale: Evaluating the Scope and Reach of a Community-Wide Initiative on Early Childhood

In implementing broad community initiatives, the ability to assess the delivery of services is a distinct challenge. Yet, understanding both the magnitude and cross-usage of services by target populations is often a precursor to effective program evaluation, program improvement and additional program planning. This research examines the extent to which a comprehensive early childhood initiative successfully reached young children and their families in a large urban county. By linking birth records and administrative datasets at the level of the individual child, the study tracks the experiences of children in respect to engagement in program services and their receipt of public benefits. The study shows both the rapid growth in programs and the reach of the program elements to the majority of newborns in the target county after 5.5 years. The research highlights the challenges of effectively using individual-level data from a variety of sources for the purposes of documenting program receipt by participants

Getting Ready for School: Piloting Universal Prekindergarten in an Urban County

Investments in high-quality early care and education have been shown to reap societal benefits across the lives of the children served. A key intervention point is in the lives of 3- to 5-year olds during the period prior to entering kindergarten. Many jurisdictions have developed broad-based prekindergarten initiatives. This study reports on a pilot universal prekindergarten program in 24 sites in the Cleveland, Ohio area. Child assessment data were collected on 204 children from early care classrooms for 3- to 5-year olds across 3 time points by trained observers using 2 standardized instruments. Changes in achievement scores were shown to be significantly predicted by race, parental education level, and whether the family spoke English as a second language, with largest gains shown among children who were most behind at baseline. The findings serve to illuminate the developmental trajectory of children before kindergarten and how data can be used to inform practice and policy

Generation of the second-harmonic Bessel beams via nonlinear Bragg diffraction

We generate conical second-harmonic radiation by transverse excitation of a two-dimensional annular periodically-poled nonlinear photonic structure with a fundamental Gaussian beam. We show that these conical waves are the far-field images of the Bessel beams generated in a crystal by parametric frequency conversion assisted by nonlinear Bragg diffraction.Comment: 4 pages, 5 figures. submitte

Space to Learn and Grow: Assessing the Capacity of a Regional Early Care and Education System

As communities across the United States work to meet the early care and education needs of young children, more research is needed to inform decision making at many levels. One key dimension of this is having clarity about the relative availability of care in light of demographic trends and geographic dispersion. The present study demonstrates a method to examine the capacity of early care programs to serve the children in a large urban county. The study takes stock of the existing early care system by comparing where the child care slots are and where the demand is—all at the neighborhood level. The existing capacity to meet the needs of 3–5 year olds could provide slots for approximately 70% of all children, though there are spatial imbalances in the location of supply and demand. The study illustrates the effective use of administrative and Census-based data to inform policy planning for children and identifies several key implications for this type of effort