Subjective Performance and the Value of Blind Evaluation ∗

The incentive and project selection effects of agent anonymity are investigated in a setting where an evaluator observes a subjective noisy signal of project quality. Although the evaluator cannot commit ex ante to an acceptance criterion, she decides up front between informed review, where the agent’s ability is directly observable, or blind review, where it is not. An ideal acceptance criterion for the evaluator balances the goals of incentive provision and project selection. Relative to this, informed review results in an excessively steep equilibrium acceptance policy: the standard applied to low-ability agents is too stringent and the standard applied to high ability agents is too lenient. Blind review in which all types face the same standard often provides better incentives, but it ignores valuable information for selecting projects. In general, the evaluator prefers a policy of blind (resp. informed) review when the ability distribution is sufficiently skewed toward high (resp. low) types or the agent’s payoff from acceptance is sufficiently high (resp. low)

Price Experimentation with Strategic Buyers

A two-period model in which a monopolist endeavors to learn about the permanent demand parameter of a specific repeat buyer is presented. The buyer may strategically reject the seller's first-period offer for one of two reasons. First, in order to conceal information (i.e., to pool), a high-valuation buyer may reject high prices that would never be accepted by a low-valuation buyer. Second, in order to reveal information (i.e., to signal), a low-valuation buyer may reject low prices that would always be accepted by a high-valuation buyer. Given this, the seller often finds it optimal to post prices that reveal no useful information. Indeed, in the equilibrium where there is no signaling, the seller never charges an informative first-period price. Learning may occur in the equilibrium where there is maximal signaling, but the scope for learning appears to be quite limited even in this case. Indeed, in order to preempt information transmission through signaling, the seller may set a first-period price strictly below the buyer's lowest possible valuation

Who Benefits from Online Privacy?

When firms can identify their past customers, they may use information about purchase histories in order to price discriminate. We present a model with a monopolist and a continuum of heterogeneous consumers, where consumers can opt out from being identified, possibly at a cost. We find that when consumers can costlessly opt out, they all individually choose privacy, which results in the highest profit for the monopolist. In fact, all consumers are better off when opting out is costly. When valuations are uniformly distributed, social surplus is non-monotonic in the cost of opting out and is highest when opting out is prohibitively costly. We introduce the notion of a privacy gatekeeper — a third party that is able to act as a privacy conduit and set the cost of opting out. We prove that the privacy gatekeeper only charges the firm in equilibrium, making privacy costless to consumers

The characteristics and treatment needs of fire setters with intellectual disability: descriptive data and comparisons between offence type

Purpose: Fire setters who have an intellectual disability (ID) are often identified as posing a particular danger to the community although relatively little is known about their characteristics, treatment, and support needs. Methodology: This study describes the characteristics of 134 residents of low, medium, and high security ID facilities in the United Kingdom who have either an index offence of arson, comparing them with those who have a violentn index offence, involving either violent or a sexual indexal offenceding. Findings: Index arson offenders who had an ID had multiple prior convictions, a history of violent offending, and a high likelihood of having a comorbid mental disorder. There were many shared characteristics across the three groups. Practical implications: The current study suggests that offenders who have ID who set fires have treatment needs that are similar to those of violent and sex offenders. It follows that fire setters who have an ID may also benefit from participating in more established offending behaviour treatment programs, such as cognitive behaviour therapy programs, developed for other types of offender. Originality: This study is one of the few which has investigated the characteristics and treatment needs of persons who have an ID who set fires. In particular, it is one of the first to compare the characteristics and treatment needs for persons with ID who set fires, to those who have committed violent and sexual offences

Multiplicative renormalizability of gluon and ghost propagators in QCD

We reformulate the coupled set of continuum equations for the renormalized gluon and ghost propagators in QCD, such that the multiplicative renormalizability of the solutions is manifest, independently of the specific form of full vertices and renormalization constants. In the Landau gauge, the equations are free of renormalization constants, and the renormalization point dependence enters only through the renormalized coupling and the renormalized propagator functions. The structure of the equations enables us to devise novel truncations with solutions that are multiplicatively renormalizable and agree with the leading order perturbative results. We show that, for infrared power law behaved propagators, the leading infrared behavior of the gluon equation is not solely determined by the ghost loop, as concluded in previous studies, but that the gluon loop, the three-gluon loop, the four-gluon loop, and even massless quarks also contribute to the infrared analysis. In our new Landau gauge truncation, the combination of gluon and ghost loop contributions seems to reject infrared power law solutions, but massless quark loops illustrate how additional contributions to the gluon vacuum polarization could reinstate these solutions. Moreover, a schematic study of the three-gluon and four-gluon loops shows that they too need to be considered in more detail before a definite conclusion about the existence of infrared power behaved gluon and ghost propagators can be reached.Comment: 13 pages, 1 figure, submitted to Phys. Rev.

Who Benefits from Online Privacy?

When firms can identify their past customers, they may use information about purchase histories in order to price discriminate. We present a model with a monopolist and a continuum of heterogeneous consumers, where consumers can opt out from being identified, possibly at a cost. We find that when consumers can costlessly opt out, they all individually choose privacy, which results in the highest profit for the monopolist. In fact, all consumers are better off when opting out is costly. When valuations are uniformly distributed, social surplus is non-monotonic in the cost of opting out and is highest when opting out is prohibitively costly. We introduce the notion of a privacy gatekeeper — a third party that is able to act as a privacy conduit and set the cost of opting out. We prove that the privacy gatekeeper only charges the firm in equilibrium, making privacy costless to consumers

Model-based Robotic Dynamic Motion Control for the Robonaut 2 Humanoid Robot

Robonaut 2 (R2), an upper-body dexterous humanoid robot, has been undergoing experimental trials on board the International Space Station (ISS) for more than a year. R2 will soon be upgraded with two climbing appendages, or legs, as well as a new integrated model-based control system. This control system satisfies two important requirements; first, that the robot can allow humans to enter its workspace during operation and second, that the robot can move its large inertia with enough precision to attach to handrails and seat track while climbing around the ISS. This is achieved by a novel control architecture that features an embedded impedance control law on the motor drivers called Multi-Loop control which is tightly interfaced with a kinematic and dynamic coordinated control system nicknamed RoboDyn that resides on centralized processors. This paper presents the integrated control algorithm as well as several test results that illustrate R2's safety features and performance

The Infrared Behavior of Gluon and Ghost Propagators in Landau Gauge QCD

A solvable systematic truncation scheme for the Dyson-Schwinger equations of Euclidean QCD in Landau gauge is presented. It implements the Slavnov-Taylor identities for the three-gluon and ghost-gluon vertices, whereas irreducible four-gluon couplings as well as the gluon-ghost and ghost-ghost scattering kernels are neglected. The infrared behavior of gluon and ghost propagators is obtained analytically: The gluon propagator vanishes for small spacelike momenta whereas the ghost propagator diverges stronger than a massless particle pole. The numerical solutions are compared with recent lattice data for these propagators. The running coupling of the renormalization scheme approaches a fixed point, $\alpha_c \simeq 9.5$, in the infrared.Comment: 4 pages, 2 figures, Revtex; revised version accepted for publication in Physical Review Letter

Short-term changes in nightlife attendance and patron intoxication following alcohol restrictions in Queensland, Australia

Background: This study aims to explore short-term changes following the introduction of alcohol restrictions (most notably 2 am to 3 am last drinks). We examined patterns of nightlife attendance, intoxication, and alcohol use among patrons shortly before and after restrictions were introduced in Fortitude Valley, Brisbane: the largest nighttime entertainment precinct of Queensland. Methods: Street-intercept patron interviews were conducted in Fortitude Valley in June (n = 497) and July (n = 562) 2016. A pre-post design was used to assess changes in time spent out drinking/partying prior to the interview, time of arrival in the precinct, pre-drinking, and blood alcohol concentration (BAC). Results: Regression models indicated that after the policy introduction, the proportion of people arriving at Fortitude Valley before 10:00 pm increased (OR = 1.38; 95% CI = 1.04, 1.82). Participants reported going out, on average, one hour earlier after the intervention (β = − 0.17; 95% CI = 0.11, 0.22). There was a decrease (RRR = 0.58; 95% CI = 0.43, 0.79) in the proportion of participants who had a high level of intoxication (BAC ≥0.10 g/dL) postintervention. No other significant differences were found. Conclusions: Earlier cessation of alcohol sales and stopping the sale of rapid intoxication drinks after midnight was associated with people arriving in Fortitude Valley earlier. Though legislative loopholes allowed some venues to continue trading to 5 am, the proportion of people in the precinct who were highly intoxicated decreased after the restriction. Further measurement will be required to determine whether the reduction has persisted