Measuring the Efficiency and Productivity of British Universities: An Application of DEA and the Malmquist Approach

This paper uses data envelopment analysis to examine the technical efficiency (TE) of 45 British universities in the period 1980/81 to 1992/93. This period was chosen primarily because it was characterized by major changes in public funding and in student : staff ratios. To shed light on the causes of variations in efficiency, TE is decomposed into pure technical efficiency (PTE), congestion efficiency (CE) and scale efficiency (SE). The analysis indicates that there was a substantial rise in the weighted geometric mean TE score during the study period, although this rise was most noticeable between 1987/88 and 1990/91. The rising TE scores are attributed largely to the gains in PTE and CE, with SE playing a minor role. The Malmquist approach is then used to distinguish between changes in technical efficiency and intertemporal shifts in the efficiency frontier. The results reveal that total factor productivity rose by 51.5% between 1980/81 and 1992/93, and that most of this increase was due to a substantial outward shift in the efficiency frontier during this period.Efficiency; Productivity; Universities; DEA; Malmquist

ARE CROP YIELDS NORMALLY DISTRIBUTED?

This paper revisits the issue of crop yield distributions using improved model specifications, estimation and testing procedures that address the methodological concerns raised in recent literature that could have invalidated previous conclusions of yield non-normality. It shows beyond reasonable doubt that some crop yield distributions are non-normal, kurtotic and right or left skewed, depending on the circumstances. A procedure to jointly estimate non-normal farm- and aggregate-level yield distributions with similar means but different variances is illustrated, and the consequences of incorrectly assuming yield normality are explored.Yield non-normality, probability distribution function models, Corn Belt yields, West Texas dryland cotton yields, Crop Production/Industries,

Thermal photon to dilepton ratio in ultra-relativistic heavy ion collisions

The ratio of transverse momentum distribution of thermal photons to dilepton has been evaluated. It is observed that this ratio reaches a plateau beyond a certain value of transverse momentum. We argue that this ratio can be used to estimate the initial temperature of the system by selecting the transverse momentum and invariance mass windows judiciously. It is demonstrated that if the radial flow is large then the plateau disappear and hence a deviation from the plateau can be used as an indicator of large radial flow. The sensitivity of the results on various input parameters has been studied.Comment: 9 pages with 11 eps figure

Watch Out for the Beast: Fear Information and Attentional Bias in Children

Although valenced information about novel animals changes the implicit and explicit fear beliefs of children (Field & Lawson, 2003), how it might lead to anxiety is unknown. One possibility, based on cognitive models of anxiety, is that fear information creates attentional biases similar to those seen in anxiety disorders. Children between 7 and 9 years old were given positive information about 1 novel animal, negative information about another, and no information about the 3rd. A pictorial dot-probe task was used, immediately or with a 24-hr delay, to test for attentional biases to the different animals. The results replicated the finding that fear information changes children's fear beliefs. Regardless of whether there was a delay, children acquired an attentional bias in the left visual field toward the animal about which they held negative beliefs compared to the control animal. These results imply a possible way in which fear information might contribute to acquired fear

Experimental evidence for radiative attachment in astrochemistry from electron attachment to NCCCCN

Electron attachment to NCCCCN, dicyanoacetylene (2-butynedinitrile), has been observed. Metastable parent anions, NCCCCN_∗, with microsecond or longer lifetimes are formed close to 0 eV electron energy with a cross section of ≥0.25 2. The stability of NCCCCN suggests that radiative attachment to NCCCCN and similar _∗ °A linear carbon chain molecules may be an important mechanism for the formation of negatively charged molecular ions in astrophysical environments. CCCN_ and CN_ fragment anions are formed at ∼3 and ∼6 eV

Cracks Cleave Crystals

The problem of finding what direction cracks should move is not completely solved. A commonly accepted way to predict crack directions is by computing the density of elastic potential energy stored well away from the crack tip, and finding a direction of crack motion to maximize the consumption of this energy. I provide here a specific case where this rule fails. The example is of a crack in a crystal. It fractures along a crystal plane, rather than in the direction normally predicted to release the most energy. Thus, a correct equation of motion for brittle cracks must take into account both energy flows that are described in conventional continuum theories and details of the environment near the tip that are not.Comment: 6 page

On the Production of Homeland Security Under True Uncertainty

Homeland security against possible terrorist attacks involves making decisions under true uncertainty. Not only are we ignorant of the form, place, and time of potential terrorist attacks, we are also largely ignorant of the likelihood of these attacks. In this paper, we conceptualize homeland security under true uncertainty as society’s immunity to unacceptable losses. We illustrate and analyze the consequences of this notion of security with a simple model of allocating a fixed budget for homeland security to defending the pathways through which a terrorist may launch an attack and to mitigating the damage from an attack that evades this defense. In this problem, immunity is the range of uncertainty about the likelihood of an attack within which the actual expected loss will not exceed some critical value. We analyze the allocation of a fixed homeland security budget to defensive and mitigative efforts to maximize immunity to alternative levels of expected loss. We show that the production of homeland security involves a fundamental trade-off between immunity and acceptable loss; that is, for fixed resources that are optimally allocated to defense and mitigation, increasing immunity requires accepting higher expected losses, and reducing acceptable expected losses requires lower immunity. Greater investments in homeland security allow society to increase its immunity to a particular expected loss, reduce the expected losses to which we are immune while holding the degree of immunity constant, or some combination of increased immunity to a lower critical expected loss.Homeland Security, Terrorism, True Uncertainty

Inspections To Avert Terrorism: Robustness Under Severe Uncertainty

Protecting against terrorist attacks requires making decisions in a world in which attack probabilities are largely unknown. The potential for very large losses encourages a conservative perspective, in particular toward decisions that are robust. But robustness, in the sense of assurance against extreme outcomes, ordinarily is not the only desideratum in uncertain environments. We adopt Yakov Ben-Haim’s (2001b) model of information gap decision making to investigate the problem of inspecting a number of similar targets when one of the targets may be attacked, but with unknown probability. We apply this to a problem of inspecting a sample of incoming shipping containers for a terrorist weapon. While it is always possible to lower the risk of a successful attack by inspecting more vessels, we show that robustness against the failure to guarantee a minimum level of expected utility might not be monotonic. Robustness modeling based on expected utility and incorporating inspection costs yields decision protocols that are a useful alternative to traditional risk analysis.Terrorism, Robustness, Severe Uncertainty, Port Security

Final state interactions and hadron quenching in cold nuclear matter

I examine the role of final state interactions in cold nuclear matter in modifying hadron production on nuclear targets with leptonic or hadronic beams. I demonstrate the extent to which available experimental data in electron-nucleus collisions can give direct information on final state effects in hadron-nucleus and nucleus-nucleus collisions. For hadron-nucleus collisions, a theoretical estimate based on a parton energy loss model tested in lepton-nucleus collisions shows a large effect on mid-rapidity hadrons at fixed target experiments. At RHIC energy, the effect is large for negative rapidity hadrons, but mild at midrapidity. This final state cold hadron quenching needs to be taken into account in jet tomographic analysis of the medium created in nucleus-nucleus collisions.Comment: 14 pages, 7 figure