Does consultation improve decision making?

This paper reports an experiment designed to test whether prior consultation within a group affects subsequent individual decision making in tasks where demonstrability of correct solutions is low. In our experiment subjects considered two paintings created by two different artists and were asked to guess which artist made each painting. We observed answers given by individuals under two treatments: in one, subjects were allowed the opportunity to consult with other participants before making their private decisions; in the other there was no such opportunity. Our primary findings are that subjects in the first treatment evaluate the opportunity to consult positively but they perform significantly worse and earn significantly less.Consultation; Decision making; Group decisions; Individual decisions

ON THE LOCATION OF THE 1-PARTICLE BRANCH OF THE SPECTRUM OF THE DISORDERED STOCHASTIC ISING MODEL

We analyse the lower non trivial part of the spectrum of the generator of the Glauber dynamics for a d-dimensional nearest neighbour Ising model with a bounded random potential. We prove conjecture 1 in [1]: for sufficently large values of the temperature, the first band of the spectrum of the generator of the process coincides with a closed non random segment of the real line

The Brownian Web: Characterization and Convergence

The Brownian Web (BW) is the random network formally consisting of the paths of coalescing one-dimensional Brownian motions starting from every space-time point in ${\mathbb R}\times{\mathbb R}$. We extend the earlier work of Arratia and of T\'oth and Werner by providing characterization and convergence results for the BW distribution, including convergence of the system of all coalescing random walkssktop/brownian web/finale/arXiv submits/bweb.tex to the BW under diffusive space-time scaling. We also provide characterization and convergence results for the Double Brownian Web, which combines the BW with its dual process of coalescing Brownian motions moving backwards in time, with forward and backward paths ``reflecting'' off each other. For the BW, deterministic space-time points are almost surely of ``type'' $(0,1)$ -- {\em zero} paths into the point from the past and exactly {\em one} path out of the point to the future; we determine the Hausdorff dimension for all types that actually occur: dimension 2 for type $(0,1)$, 3/2 for $(1,1)$ and $(0,2)$, 1 for $(1,2)$, and 0 for $(2,1)$ and $(0,3)$.Comment: 52 pages with 4 figure

Aid allocation and aid effectiveness: An empirical analysis

The paper performs aid allocation analysis using OECD-DAC data covering 20 aid donors and 176 recipients over the period 1980-2003. We improve upon earlier work in this area by employing inter alia the variable ‘past outcome’ measuring aid effectiveness in order to link together aid allocation and aid effectiveness. In line with previous work, we also account for both altruistic and selfish donor motives in the empirical analysis. As expected, empirical results based on Tobit estimates of aid allocation for individual donors vary quite significantly among donors. We also test the robustness of our results by estimating individual regressions for the major donors over the period 1990-2003 in view of major events in the aid arena during that time that could potentially have an impact on the aid allocation process. Our results seem to be similar to those derived over the 1980-2003 period, thus implying that this was not the case. Overall, both altruistic and selfish donor motives seem to motivate aid allocation for most donors over the two periods under examination. However, when we further restrict our time dimension to the 1999-2003 period, some important policy changes with regard to selectivity seem to emerge for a small group of donor countries

Does consultation improve decision-making?

This paper reports an experiment designed to test whether prior consultation within a group affects subsequent individual decision-making in tasks where demonstrability of correct solutions is low. In our experiment, subjects considered two paintings created by two different artists and were asked to guess which artist made each painting. We observed answers given by individuals under two treatments: In one, subjects were allowed the opportunity to consult with other participants before making their private decisions; in the other, there was no such opportunity. Our primary findings are that subjects in the first treatment evaluate the opportunity to consult positively, but they perform significantly worse and earn significantly less

Multitasking network with fast noise

We consider the multitasking associative network in the low-storage limit and we study its phase diagram with respect to the noise level $T$ and the degree $d$ of dilution in pattern entries. We find that the system is characterized by a rich variety of stable states, among which pure states, parallel retrieval states, hierarchically organized states and symmetric mixtures (remarkably, both even and odd), whose complexity increases as the number of patterns $P$ grows. The analysis is performed both analytically and numerically: Exploiting techniques based on partial differential equations, allows us to get the self-consistencies for the order parameters. Such self-consistence equations are then solved and the solutions are further checked through stability theory to catalog their organizations into the phase diagram, which is completely outlined at the end. This is a further step toward the understanding of spontaneous parallel processing in associative networks