Demand and Pricing in Electricity Markets: Evidence from San Diego During California's Energy Crisis

We study the electricity consumption of San Diego-area households following a series of price changes and related events during California's energy crisis in 2000-01. The analysis uses a five-year panel of disaggregate billing and weather data for a random sample of 70,000 households. In contrast to prior work, these data allow us to proceed without behavioral assumptions regarding a consumer's knowledge of energy prices. We find that after a rapid price increase in summer 2000, consumption fell substantially over about 60 days, averaging 12% per household; consumption then rebounded to within 3% of pre-crisis levels after a price cap was imposed. Under the price cap public appeals for energy conservation and a remunerative voluntary conservation program had significant, but transitory, effects. Further, a large share of households reduced electricity consumption substantially (over 10%) but saved small monetary amounts ($10 or less). Overall, the results indicate consumers may be far more responsive to pecuniary and non-pecuniary incentives for altering their energy use than is commonly believed.

Household Electricity Demand, Revisited

Recent efforts to restructure and partially deregulate electricity markets have renewed interest in understanding how consumers respond to price changes. Several interrelated problems complicate demand analyses of these markets, including nonlinear pricing, heterogeneity in households' price sensitivities, and data aggregation. This paper formulates a model of household electricity demand that addresses these difficulties. We estimate the model using data for a representative sample of California households, and summarize how electricity demand elasticities vary in that state. We then use the model to analyze the electricity consumption and expenditure effects of recent tariff structure changes in California.

Evaluating Welfare with Nonlinear Prices

This paper examines how to evaluate consumer welfare when consumers face nonlinear prices. This problem arises in many settings, such as devising optimal pricing strategies for firms, assessing how price discrimination affects consumers, and evaluating the efficiency costs of many transfer programs in the public sector. We extend prior methods to accommodate a broad range of modern pricing practices, including menus of pricing plans. This analysis yields a simpler and more general technique for evaluating exact consumer surplus changes in settings where consumers face nonlinear prices. We illustrate our method using recent changes in mobile phone service plans.

Responsible Corporate Officers and Section 113(C)(6) of the Clean Air Act: The Dormant Provision with a Useful Function

The flurry of criticism over the addition of the responsible corporate officer provision to the Clean Air Act has focused on its application of strict liability and the mens rea requirement. Dotterweich and Park both applied what appeared to be strict liability for violations of the Food, Drug and Cosmetics Act. The fear was that non-culpable corporate officers would be held strictly liable, face not misdemeanor sanctions but the most severe felony penalties. This fear was unfounded. No corporate officer was held strictly liable; public welfare offenses evolved as the courts conscientiously applied the “knowing” requirement to environmental statutes and the RCO provision. However, traditional criminal law theory and case law support another use of the RCO provision, one in which the statute is the source of a duty for a corporate officer who is in responsible relation to a public danger: the duty to actively seek out to prevent or remedy violations. This paper will explore the value of defining the RCO provision as the actus reus of a crime—the omission or breach of a statutory duty. This theory can further the environmental regulatory program by deterring would be violators and by increasing compliance, a value that exists despite the fact that the RCO provision is rarely used to prosecute corporate officers. Part II will trace the evolution of criminal provisions and the addition of the responsible corporate officer clause in environmental statutes. Part III will the follow the case law that has slowly evolved. Part IV will discuss why the RCO provision is not used more often, and how it nevertheless serves an important function in environmental law. Part V will conclude with suggested improvements of the legislature could clarify how and when the RCO doctrine should apply

Multi-epoch Sub-arcsecond [Fe II] Spectroimaging of the DG Tau Outflows with NIFS. II. On the Nature of the Bipolar Outflow Asymmetry

The origin of bipolar outflow asymmetry in young stellar objects (YSOs) remains poorly understood. It may be due to an intrinsically asymmetric outflow launch mechanism, or it may be caused by the effects of the ambient medium surrounding the YSO. Answering this question is an important step in understanding outflow launching. We have investigated the bipolar outflows driven by the T Tauri star DG Tauri on scales of hundreds of AU, using the Near-infrared Integral Field Spectrograph (NIFS) on Gemini North. The approaching outflow consists of a well-collimated jet, nested within a lower-velocity disc wind. The receding outflow is composed of a single-component bubble-like structure. We analyse the kinemat- ics of the receding outflow using kinetic models, and determine that it is a quasi-stationary bubble with an expanding internal velocity field. We propose that this bubble forms because the receding counterjet from DG Tau is obstructed by a clumpy ambient medium above the circumstellar disc surface, based on similarities between this structure and those found in the modeling of active galactic nuclei outflows. We find evidence of interaction between the obscured counterjet and clumpy ambient material, which we attribute to the large molecular envelope around the DG Tau system. An analytical model of a momentum-driven bubble is shown to be consistent with our interpretation. We conclude that the bipolar outflow from DG Tau is intrinsically symmetric, and the observed asymmetries are due to environmental effects. This mechanism can potentially be used to explain the observed bipolar asymmetries in other YSO outflows.Comment: 16 pages, 10 figures, accepted for publication in MNRA

Turbulent mixing layers in supersonic protostellar outflows, with application to DG Tauri

Turbulent entrainment processes may play an important role in the outflows from young stellar objects at all stages of their evolution. In particular, lateral entrainment of ambient material by high-velocity, well-collimated protostellar jets may be the cause of the multiple emission-line velocity components observed in the microjet-scale outflows driven by classical T Tauri stars. Intermediate-velocity outflow components may be emitted by a turbulent, shock- excited mixing layer along the boundaries of the jet. We present a formalism for describing such a mixing layer based on Reynolds decomposition of quantities measuring fundamental properties of the gas. In this model, the molecular wind from large disc radii provides a continual supply of material for entrainment. We calculate the total stress profile in the mixing layer, which allows us to estimate the dissipation of turbulent energy, and hence the luminosity of the layer. We utilize MAPPINGS IV shock models to determine the fraction of total emission that occurs in [Fe II] 1.644 {\mu}m line emission in order to facilitate comparison to previous observations of the young stellar object DG Tauri. Our model accurately estimates the luminosity and changes in mass outflow rate of the intermediate-velocity component of the DG Tau approaching outflow. Therefore, we propose that this component represents a turbulent mixing layer surrounding the well-collimated jet in this object. Finally, we compare and contrast our model to previous work in the field.Comment: 18 pages, 13 figures, accepted for publication in MNRA

Moving frames: difference and differential-difference Lagrangians

This paper develops moving frame theory for partial difference equations and for differential-difference equations with one continuous independent variable. In each case, the theory is applied to the invariant calculus of variations and the equivariant formulation of the conservation laws arising from Noether's Theorem. The differential-difference theory is not merely an amalgam of the differential and difference theories, but has additional features that reflect the need for the group action to preserve the prolongation structure. Projectable moving frames are introduced; these cause the invariant derivative operator to commute with shifts in the discrete variables. Examples include a Toda-type equation and a method of lines semi-discretization of the Nonlinear Schr\"odinger Equation.Comment: 28 pages, 3 figure

Evidence for Orbital Order and its Relation to Superconductivity in FeSe0.4Te0.6

The emergence of nematic electronic states accompanied by a structural phase transition is a recurring theme in many correlated electron materials, including the high-temperature copper oxide- and iron-based superconductors. We provide evidence for nematic electronic states in the iron-chalcogenide superconductor FeSe0.4Te0.6 from quasi-particle scattering detected in spectroscopic maps. The symmetry-breaking states persist above Tc into the normal state. We interpret the scattering patterns by comparison with quasi-particle interference patterns obtained from a tight-binding model, accounting for orbital ordering. The relation to superconductivity and the influence on the coherence length are discussed.Comment: 5 pages, 5 figures, updated with published versio