An adverse social welfare effect of quadruply gainful trade

Acknowledging that individuals dislike having low relative income renders trade less attractive when seen as a technology that integrates two economies by merging separate social spheres into one. We define a “trembling trade” as a situation in which gains from trade are less than losses in relative income, with the result that global social welfare is reduced. We show that a “trembling trade” can arise even when trade is more gainful in four ways: through trade the absolute income of everyone increases, the income gap in both economies is reduced, as is the income gap between the trading economies. However, trade brings populations, economies, or markets that were not previously connected closer together in social space. As a consequence, separate social spheres merge, and people’s social space and their comparators are altered. Assuming that people like high (absolute) income and dislike low relative income, the aggregate increase in unhappiness caused by the trade-induced escalation in relative deprivation can result in a negative overall impact of trade on (utilitarian-measured) social welfare, if the absolute income gains are not large enough to mitigate the relative income losses

Turning relative deprivation into a performance incentive device

The inclination of individuals to improve their performance when it lags behind that of others with whom they naturally compare themselves can be harnessed to optimize the individuals’ effort in work and study. In a given set of individuals, we characterize each individual by his relative deprivation, which measures by how much the individual trails behind other individuals in the set doing better than him. We seek to divide the set into an exogenously predetermined number of groups (subsets) in order to maximize aggregate relative deprivation, so as to ensure that the incentive for the individuals to work or study harder because of unfavorable comparison with others is at its strongest. We find that the solution to this problem depends only on the individuals’ ordinally-measured levels of performance independent of the performance of comparators

Switching queues, cultural conventions, and social welfare

We use queuing-related behavior as an instrument for assessing the social appeal of alternative cultural norms. Specifically, we study the behavior of rational and sophisticated individuals who stand in a given queue waiting to be served, and who, in order to speed up the process, consider switching to another queue. We look at two regimes that govern the possible order in which the individuals stand should they switch to the other queue: a regime in which cultural convention, social norms, and basic notions of fairness require that the order in the initial queue is preserved, and a regime without such cultural inhibitions, in which case the order in the other queue is random, with each configuration or sequence being equally likely. We seek to find out whether in these two regimes the aggregate of the behaviors of self-interested individuals adds up to the social optimum defined as the shortest possible total waiting time. To do this, we draw on a Nash Equilibrium setting. We find that in the case of the preserved order, the equilibrium outcomes are always socially optimal. However, in the case of the random order, unless the number of individuals is small, the equilibrium outcomes are not socially optimal

Follow-the-Regularized-Leader Routes to Chaos in Routing Games

We study the emergence of chaotic behavior of Follow-the-Regularized Leader (FoReL) dynamics in games. We focus on the effects of increasing the population size or the scale of costs in congestion games, and generalize recent results on unstable, chaotic behaviors in the Multiplicative Weights Update dynamics to a much larger class of FoReL dynamics. We establish that, even in simple linear non-atomic congestion games with two parallel links and \emph{any} fixed learning rate, unless the game is fully symmetric, increasing the population size or the scale of costs causes learning dynamics to becomes unstable and eventually chaotic, in the sense of Li-Yorke and positive topological entropy. Furthermore, we prove the existence of novel non-standard phenomena such as the coexistence of stable Nash equilibria and chaos in the same game. We also observe the simultaneous creation of a chaotic attractor as another chaotic attractor gets destroyed. Lastly, although FoReL dynamics can be strange and non-equilibrating, we prove that the time average still converges to an \emph{exact} equilibrium for any choice of learning rate and any scale of costs

SOLARIS National Synchrotron Radiation Centre in Krakow, Poland

The SOLARIS synchrotron located in Krakow, Poland, is a third-generation light source operating at medium electron energy. The first synchrotron light was observed in 2015, and the consequent development of infrastructure lead to the first users’ experiments at soft X-ray energies in 2018. Presently, SOLARIS expands its operation towards hard X-rays with continuous developments of the beamlines and concurrent infrastructure. In the following, we will summarize the SOLARIS synchrotron design, and describe the beamlines and research infrastructure together with the main performance parameters, upgrade, and development plans

Differentiation of bone density over cover of the skull in the aspect of sexual dimorphism. Model studies.

Celem pracy było porównanie względnej gęstości fragmentu kości ciemieniowej w aspekcie dymorfizmu płciowego. Przedmiotem analizy było 28 czaszek poddanych skanowaniu tomografem komputerowym. W celu precyzyjnego wyodrębnienia gąbczastej struktury tkanki kostnej konieczna była transformacja zdjęcia w skali szarości. Zsumowana liczba pikseli oraz ich wartości pozwoliły na obliczenie gęstości średniej oraz objętości mierzonego fragmentu. Dane te w zestawiono z klasycznymi pomiarami antropologicznymi. Tylko w grupie wiekowej maturus wystąpiła istotna statystycznie różnica w obrębie płci. Prawdopodobnie powodem jest przygotowanie do utraty masy kostnej i wiąże się z wyższymi u kobiet maksymalnymi wartościami koncentracji estrogenu. Ponadto, przypuszcza się, że także relatywnie słabsze napięcia w odniesieniu do mniejszych objętość czaszki mogą powodować wyższą gęstość w tym ważnym obszarze.Aim of thesis is a comparison between sexes their traits in relation to relative density of parietal bone. Chosen region starts with end of coronal suture impact visible on CT image and goes through next ten slices from 28 skulls respectively. Downwardly is equal with the border of trabecular bone. It was necessary to change basic image parameters to measure exactly internal layer of bone. Value of every picture in greyscale has been revealed and counted. Sum of them allowed to calculate volume. These data have been compared with classic anthropological measurements. Only in maturus group statistically significant gender-difference has been revealed. Probably the reason is a preparation to late-age bone loss and is a result of the highest peaks of oestrogen concentration in case of women. Additionally, it is supposed that also relatively weaker tensions in relation to smaller skull volume can determine higher density within this crucial area

A pure theory of population distribution when preferences are ordinal

We model an environment in which individuals prefer to be in a space in which their rank is higher, be it a social space, a geographical space, a work environment, or any other comparison sphere which we refer to in this paper, and without loss of generality, as a region. When the individuals can choose between more than two regions, we inquire: (i) whether a steady-state distribution of the population is reached; (ii) how long it will take to reach a steady state; and (iii) if a steady state obtains, whether at the steady state social welfare is maximized. Despite the fact that when there are three or more regions the mobility paths are more intricate than when there are only two regions, we prove that a steady-state distribution of the population across the regions is reached; we identify the upper bound of the number of time periods that it will take to reach the steady-state distribution; and we show that the steady-state distribution maximizes social welfare. This last result is surprising: even though the individuals act of their own accord, they achieve the socially preferred outcome

An adverse social welfare effect of guadruply gainful trade

Acknowledging that individuals dislike having low relative income renders trade less attractive when seen as a technology that integrates two economies by merging separate social spheres into one. We define a “trembling trade” as a situation in which gains from trade are less than losses in relative income, with the result that global social welfare is reduced. We show that a “trembling trade” can arise even when trade is more gainful in four ways: through trade the absolute income of everyone increases, the income gap in both economies is reduced, as is the income gap between the trading economies. However, trade brings populations, economies, or markets that were not previously connected closer together in social space. As a consequence, separate social spheres merge, and people’s social space and their comparators are altered. Assuming that people like high (absolute) income and dislike low relative income, the aggregate increase in unhappiness caused by the trade-induced escalation in relative deprivation can result in a negative overall impact of trade on (utilitarian-measured) social welfare, if the absolute income gains are not large enough to mitigate the relative income losses