The effects of equitability policies on the ZEV market: Evidence from California’s Clean Vehicle Rebate Project

California’s Clean Vehicle Rebate Program (CVRP) is the largest zero-emissions vehicle (ZEV) incentive program in the United States. This policy brief summarizes how changes to the CVRP incentive structure may have affected California's ZEV market

Spectral Gap in the Ferromagnetic Heisenberg Spin-1⁄2 Quantum Spin Chain

The ferromagnetic Heisenberg spin-1⁄2 quantum spin chain describes a quantum spin system of spin-1⁄2 particles on a one-dimensional lattice. In the thermodynamic limit, the spectral gap of this system closes at rate of O(n−2). We demonstrate this by proving an upper bound on the spectral gap using the variational principle and a lower bound using the martingale method

Sharing Mobility Data for Planning and Policy Research

A California Public Utilities Commission (CPUC) rulemaking and possible legislative action in 2020 could affect data sharing requirements, with implications for shared mobility providers. The purpose of this brief is to inform this regulatory and legislative decision-making. We solicited policy and planning questions and data needs for shared mobility from within the University of California Institute of Transportation Studies research network. We defined shared mobility as including shared mobility devices, such as e-bikes and e-scooters, and transportation network companies (TNCs). We evaluated whether data shared in accordance with each of six mobility data specifications could be used to support analyses that would answer these questions. We then defined three approaches to data sharing and analysis to address these and other questions, presenting the advantages and disadvantages of each. This brief does not address the full breadth of the questions raised in the CPUC rulemaking nor does it introduce the complexities of this topic. Beyond the scope of this brief are issues of user privacy, the legal authority for sharing data, and contractual or requirements for each possible model of data sharing and analysis

Beyond the Numbers: Data Use for Continuous Improvement of Programs Serving Disconnected Youth

The American Youth Policy Forum (AYPF) conducted a series of in-depth case studies to examine how three programs which serve a disconnected youth population are utilizing data as a tool for continuous program improvement and ongoing accountability. The resulting publication, Beyond the Numbers: Data Use for Continuous Improvement of Programs Serving Disconnected Youth, describes data collection and use at three successful programs, and distills the key lessons learned and issues to consider both for practitioners and policymakers aiming to improve outcomes for the disconnected youth population

Generalized Costs of Travel by Solo and Pooled Ridesourcing vs. Privately Owned Vehicles, and Policy Implications

The emergence of “3 Revolutions” in transportation (automation, electrification and shared mobility) presents a range of questions regarding how consumers will travel in the future, and under what conditions there may be rapid adoption of various services. These include individual on-demand taxi-style services, shared mobility in pooled services, and use of public transit, all with or without drivers. There is now enough data and estimates on the costs of these service combinations, and in some cases ridership data, to consider how consumers are making choices and could do so in the future as things evolve. This project involved: (a) reviewing existing literature and data on consumer mode and vehicle choice; (b) developing new “generalized cost” estimates that combine monetary and non-monetary (e.g., hedonic) components of travel choice, notably incorporating value of time; and (c) conducting a comparison of monetary and generalized trip cost for a range of trip types across travel options in the near term (2020) and longer term (2030-35). Three main travel options were considered: privately owned vehicles, ridesourced solo trips, and ridesourced pooled trips. Consideration of internal combustion vs. battery electric and, in the longer term, automated technology was also core to the analysis. The trips considered include urban and suburban types in the San Francisco metro area, using actual trip characteristics. The results suggest that in the near-term, solo ridesourcing is likely to be perceived as significantly more expensive (in terms of monetary and time costs) than pooled ridesourcing or solo private vehicle trips except for those with a very high value of time. Solo ridesourcing does better in dense, slow, urban trips than in faster suburban trips. In the longer term, with automated driverless vehicles, solo ridesourcing could become the cheapest mode for many travelers in a range of situations. This report includes an initial consideration of the implications of these policies for affecting travel choices, presumably to push choices toward pooled ridesourcing as a sustainable option. VMT-based pricing, pricing that could be adjusted with vehicle occupancy, and parking-related approaches are described. A large price signal might be needed to shift travel, given some of the differences in generalized cost found in this analysis

Geometric ergodicity of Gibbs samplers for Bayesian error-in-variable regression

We consider Bayesian error-in-variable (EIV) linear regression accounting for additional additive Gaussian error in the features and response. We construct 3-variable deterministic scan Gibbs samplers for EIV regression models using classical and Berkson errors with independent normal and inverse-gamma priors. We prove these Gibbs samplers are always geometrically ergodic which ensures a central limit theorem for many time averages from the Markov chains

We Need to Change the Language we use to Describe Individuals with Substance Use Issues

People with substance use disorders (SUDs) are highly stigmatized worldwide. This research brief describes the results from several studies on unconscious bias and negative language used to describe individuals with SUDs

The Microbial Populations Of The Intertidal Zone Of Two Sandy Beaches

This study was based on an examination of the bacterial and fungal populations in the intertidal zone of two sandy beaches. The two beaches were near Hartlepool, Cleveland, and one was selected as being heavily polluted by a major sewage outfall whilst the other appeared to be relatively unpolluted. Several physical and chemical characteristics of the two beaches were also assessed. The results show that there were resident populations of heterotrophic bacteria present in both beaches. These populations consisted principally of species of Pseudomonas. Fungi were also isolated from both sites. Most of the genera recorded are normally regarded as terrestial. There was an inverse correlation between the numbers of bacteria and fungi in both beaches. No major qualitative or quantitative difference was found between the microbiology of the polluted and the non-polluted beach. Human faecal bacteria were not found in either sediment. Experiments carried out on the effects of adsorption in these intertidal sands emphasised the importance of this phenomenon in the microbial ecology of these substrates. Desiccation was shown to profoundly change the bacterial flora of sand but water loss was considered to be minimal in the zones subject to twice daily inundation

Digital Disinformation Is a Threat to Public Health

In times of public health crises, like COVID-19, a country’s residents must be able to access valid, timely, and evidence-based information that can guide behaviors and prevention strategies. Disinformation undermines these efforts and represents an existential threat to U.S. population health

“Right to Work” and Life or Death for Georgia Teachers

Georgia is a “right to work” state, in which teachers can be fired or have their state license revoked if they strike or utilize collective bargaining. This leaves few legal options for teachers to challenge the state mandate to reopen without adequate preparation