Scoring rules in experimental procurement

We report the results of an experiment where subjects compete for procurement contracts to be awarded by means of a scoring auction. Two experimental conditions are considered, depending on the relative weight of quality vs price in the scoring rule. We show that different quality-price weights dramatically alter the strategic environment and affect efficiency. Our evidence shows that each weighting better delivers against a matching objective function than using a scoring rule which misrepresents the buyer’s objective function. Nonetheless, there are large deviations in how each performs, with the higher weight on quality delivering much greater efficiency evaluated against its own objective function than a low weight on quality evaluated against its own objective function, despite the higher quality weight inducing higher deviations from equilibrium. We propose a “mediation analysis” to show that the “direct effect” (due to the different strategic properties of the induced game-forms) outweighs the “indirect” one (how the different game-forms affect out-of-equilibrium behavior). We also perform a structural estimation of the Quantal Response Equilibrium induced by subjects’ behavior, where we find that subjects are risk averse and noisy play affects behavior in the direction of underbidding

Acid-Stable Serine Proteinase Inhibitors in the Urine of Alzheimer Disease Subjects

A comparative study of the levels of acid-stable proteinase inhibitors (kallikrein and trypsin inhibitors) in the urine of healthy and Alzheimer subjects, of both sexes, has been performed. A preliminary characterization of the purified inhibitors indicates that the urinary antitryptic activity is accounted for by the presence of the well known Urinary Trypsin Inhibitor (UTI) while an apparently new molecule appears to be responsible for the anti kallikrein activity. The urinary levels of kallikrein inhibitors are very similar in healthy and sick subjects while the levels of trypsin inhibitors appear significatively increased in Alzheimer subjects of both sexes. The data presented here support the hypothesis that unpaired proteolytic processes could be involved in the pathogenesis of Alzheimer's disease and suggest that the levels of urinary acid-stable inhibitors may prove to be useful markers of the disease

Sequence of cycles and transitions to chaos in a modified Goodwin’s Growth Cycle model

The model introduced by Goodwin [1967] in “A Growth Cycle” represents a milestone in the nonlinear modeling of economic dynamics. On the basis of a few simple assumptions the Goodwin Model (GM) is formulated exactly as the well-known Lotka–Volterra system in terms of the two variables “wage share” and “employment rate”. A number of extensions have been proposed with the aim to make the model more robust in particular to obtain structural stability lacking in GM original formulation. We propose a new extension that: (a) removes the limiting hypothesis of “Harrod-neutral” technical progress: (b) on the line of Lotka–Volterra models with adaptation introduces the concept of “memory” which plays a relevant role in the dynamics of economic systems. As a consequence an additional equation appears the validity of the model is substantially extended and a rich phenomenology is obtained transition to chaotic behavior via period-doubling bifurcation