A Trackable Model of Reciprocity and Fairness.

We introduced a parametric model of other-regarding preferences in which my emotional state determines the marginal rate of substitution between my own and other' payoffs, and thus my subsequent choices. In turn, my emotional state responds to relative status and to the kindness or unkindness of others' choices. Structural estimations of this model with six existing data sets demonstrate that other-regarding preferences depend on status, reciprocity, and perceived property rights.RECIPROCITY ; MARGINAL RATE OF SUBSTITUTION ; PAYOFFS

T cell specific adaptor protein (TSAd) promotes interaction of Nck with Lck and SLP-76 in T cells

Background: The Lck and Src binding adaptor protein TSAd (T cell specific adaptor) regulates actin polymerization in T cells and endothelial cells. The molecular details as to how TSAd regulates this process remain to be elucidated. Results: To identify novel interaction partners for TSAd, we used a scoring matrix-assisted ligand algorithm (SMALI), and found that the Src homology 2 (SH2) domain of the actin regulator Non-catalytic region of tyrosine kinase adaptor protein (Nck) potentially binds to TSAd phosphorylated on Tyr280 (pTyr280) and pTyr305. These predictions were confirmed by peptide array analysis, showing direct binding of recombinant Nck SH2 to both pTyr280 and pTyr305 on TSAd. In addition, the SH3 domains of Nck interacted with the proline rich region (PRR) of TSAd. Pull-down and immunoprecipitation experiments further confirmed the Nck-TSAd interactions through Nck SH2 and SH3 domains. In line with this Nck and TSAd co-localized in Jurkat cells as assessed by confocal microscopy and imaging flow cytometry. Co-immunoprecipitation experiments in Jurkat TAg cells lacking TSAd revealed that TSAd promotes interaction of Nck with Lck and SLP-76, but not Vav1. TSAd expressing Jurkat cells contained more polymerized actin, an effect dependent on TSAd exon 7, which includes interactions sites for both Nck and Lck. Conclusions: TSAd binds to and co-localizes with Nck. Expression of TSAd increases both Nck-Lck and Nck-SLP-76 interaction in T cells. Recruitment of Lck and SLP-76 to Nck by TSAd could be one mechanism by which TSAd promotes actin polymerization in activated T cells. © 2015 Hem et al

The Competitive Market Paradox.

The competitive market model is a paradoxical. In perfect competition, agents cannot influence price: they only select an output quantity. Such passive behavior doesn’t conform to the intuitive notion of competition. This paper describes an experiment which demonstrates that near or even at a competitive equilibrium price, competition is undiminished. A substantial difference between the performance of sellers and buyers frequently results from this vigorous competition, even with low price variability and approximate efficiency. In double auction experiment sessions conducted with both automated and human agents, exogenous variation of the pace of asks and bids of automated agents demonstrates that the performance difference between sellers and buyers results primarily from a difference between the pace of asks and bids. If the buyers’ pace is slower than sellers’ pace, buyers make price concessions less frequently than sellers so that prices move below the equilibrium price. Then more buyers become active and fewer sellers remain active. Prices stabilize when changes to the numbers of active buyers and sellers offset the superior bargaining capability of one side or the other. In competitive equilibrium, to a first approximation agents are price takers, but that doesn’t preclude vigorous competition: competitive behavior moves to the dimension of bargaining pace.Bargaining ; bounded rationality ; competitive equilibrium ; double auction ; experimental economics

Individual Rationality and Market Efficiency

Smith’s (1962) demonstration that prices and allocations quickly converge to the competitive equilibrium in the continuous double auction (CDA) remains one of the most important results in experimental economics. Market experiments and exchange models have added considerably to our knowledge of how markets reach equilibrium, and how they respond to disruptions. Perhaps the best-known model of exchange in CDA market experiments is the random behavior “zero-intelligence” (ZI) model by Gode and Sunder (1993). They argue that the CDA generates efficient allocations and “convergence of transaction prices to the proximity of the theoretical equilibrium price,” provided only that agents meet their budget constraints. We demonstrate that prices do not converge in their simulations. Their budget constraint requires that a buyer’s currency never exceeds her commodity value, which is an unnatural restriction. Their conclusion that market efficiency results from the structure of the CDA independent of traders’ profit seeking behavior rests on their claim that the constraints that they impose are a part of the market institution. We show that actually they impose individual rationality. Misinterpretation of this behavioural constraint has lead to unproductive debate on market adjustment processes

Q-Strategy: A Bidding Strategy for Market-Based Allocation of Grid Services

The application of autonomous agents by the provisioning and usage of computational services is an attractive research field. Various methods and technologies in the area of artificial intelligence, statistics and economics are playing together to achieve i) autonomic service provisioning and usage of Grid services, to invent ii) competitive bidding strategies for widely used market mechanisms and to iii) incentivize consumers and providers to use such market-based systems. The contributions of the paper are threefold. First, we present a bidding agent framework for implementing artificial bidding agents, supporting consumers and providers in technical and economic preference elicitation as well as automated bid generation by the requesting and provisioning of Grid services. Secondly, we introduce a novel consumer-side bidding strategy, which enables a goal-oriented and strategic behavior by the generation and submission of consumer service requests and selection of provider offers. Thirdly, we evaluate and compare the Q-strategy, implemented within the presented framework, against the Truth-Telling bidding strategy in three mechanisms – a centralized CDA, a decentralized on-line machine scheduling and a FIFO-scheduling mechanisms

How do markets manage water resources? An experiment

We experimentally test how a private monopoly, a duopoly and a public utility allocate water of differing qualities to households and farmers. Most of our results are in line with the theoretical predictions. Overexploitation of the resources is observed independently of the market structure. Stock depletion for the public utility is the fastest, followed by the private duopoly and private monopoly. On the positive aspects of centralized public management, we find that the average quality to price ratio offered by the public monopoly is substantially higher than that offered by the private monopoly or duopoly

Adaptive-Aggressive Traders Don't Dominate

For more than a decade Vytelingum's Adaptive-Aggressive (AA) algorithm has been recognized as the best-performing automated auction-market trading-agent strategy currently known in the AI/Agents literature; in this paper, we demonstrate that it is in fact routinely outperformed by another algorithm when exhaustively tested across a sufficiently wide range of market scenarios. The novel step taken here is to use large-scale compute facilities to brute-force exhaustively evaluate AA in a variety of market environments based on those used for testing it in the original publications. Our results show that even in these simple environments AA is consistently out-performed by IBM's GDX algorithm, first published in 2002. We summarize here results from more than one million market simulation experiments, orders of magnitude more testing than was reported in the original publications that first introduced AA. A 2019 ICAART paper by Cliff claimed that AA's failings were revealed by testing it in more realistic experiments, with conditions closer to those found in real financial markets, but here we demonstrate that even in the simple experiment conditions that were used in the original AA papers, exhaustive testing shows AA to be outperformed by GDX. We close this paper with a discussion of the methodological implications of our work: any results from previous papers where any one trading algorithm is claimed to be superior to others on the basis of only a few thousand trials are probably best treated with some suspicion now. The rise of cloud computing means that the compute-power necessary to subject trading algorithms to millions of trials over a wide range of conditions is readily available at reasonable cost: we should make use of this; exhaustive testing such as is shown here should be the norm in future evaluations and comparisons of new trading algorithms.Comment: To be published as a chapter in "Agents and Artificial Intelligence" edited by Jaap van den Herik, Ana Paula Rocha, and Luc Steels; forthcoming 2019/2020. 24 Pages, 1 Figure, 7 Table

Common genetic variation and susceptibility to partial epilepsies: a genome-wide association study

Partial epilepsies have a substantial heritability. However, the actual genetic causes are largely unknown. In contrast to many other common diseases for which genetic association-studies have successfully revealed common variants associated with disease risk, the role of common variation in partial epilepsies has not yet been explored in a well-powered study. We undertook a genome-wide association-study to identify common variants which influence risk for epilepsy shared amongst partial epilepsy syndromes, in 3445 patients and 6935 controls of European ancestry. We did not identify any genome-wide significant association. A few single nucleotide polymorphisms may warrant further investigation. We exclude common genetic variants with effect sizes above a modest 1.3 odds ratio for a single variant as contributors to genetic susceptibility shared across the partial epilepsies. We show that, at best, common genetic variation can only have a modest role in predisposition to the partial epilepsies when considered across syndromes in Europeans. The genetic architecture of the partial epilepsies is likely to be very complex, reflecting genotypic and phenotypic heterogeneity. Larger meta-analyses are required to identify variants of smaller effect sizes (odds ratio <1.3) or syndrome-specific variants. Further, our results suggest research efforts should also be directed towards identifying the multiple rare variants likely to account for at least part of the heritability of the partial epilepsies. Data emerging from genome-wide association-studies will be valuable during the next serious challenge of interpreting all the genetic variation emerging from whole-genome sequencing studie

Analyse av effekttoppreduksjon ved bruk av batteri i mikronett på Brattørkaia

Oppgaven tar for seg et mikronett på Brattørkaia i Trondheim med de fire kraftkundene Brattørkaia 15, 16 og 17a, en elbusslader, i tillegg til effektbehovet i en parkeringskjeller under Brattørkaia 16 og 17a. Brattørkaia 17a heter Powerhouse Brattørkaia, og er verdens nordligste plusshus. I oppgaven vil det være fokus på hvordan et batteri kun brukes til effekttoppreduksjon, og ulike bruksmetoder og størrelser av batteriet. Gjennom hele oppgaven gjøres det separate beregninger ved det tekniske og økonomiske aspektet, og miljøaspektet til prosjektet vurderes kort. Lønnsomhet er gjennomgående en viktig faktor i oppgaven. Oppgaven begrenses til fire batteristørrelser, fire bruksmetoder av batteriene, og tre “ladetilfeller” for effektforbruket til elbilladerne. Per dags dato er det ikke gitt dispensasjon til utbyggingen av mikronettet, men i oppgaven vurderes det økonomiske utfallet dersom dispensasjon blir gitt. Det er da antatt fri flyt av strøm innad i mikronettet; kostnadsfordelingen innad i mikronettet er ikke vurdert. Resultatet fremstiller de tekniske og økonomiske analysene separat for alle undersøkelsene. Disse gå ut på kostnadsbesparelse ved mikronettsammenslåing, hvordan et batteri kan brukes til effekttoppreduksjon, og hvordan ulike batteristørrelser kan brukes i mikronettet. Lønnsomheten vurderes gjennomgående ut fra prosjektets nåverdi, og det finnes løsninger for at lønnsomheten skal øke. Resultatene viser at utbygging av mikronettet vil gi en årlig kostnadsbesparelse for de fire kundene i mikronettet. Den beste bruksmetoden for batteriet er at det ved overskudd av energi først lades opp på solkraft, og deretter selger opptil 100 kW til nettet. Etter effekttoppreduksjonen er ferdig for dagen, lades batteriet helt ut før det igjen lades opp på natten med billigere kraft. Resultatene viste også at en batteriinvestering ikke er lønnsom med gitt dagens innkjøpspris, men med pristrender fra dagens batterimarked skal det være mulig å finne billigere batterier på markedet både i dag og framtiden som kan gi prosjektet positiv nåverdi. I diskusjonen blir fordeler og ulemper ved batteriinvesteringen, bruksmetodene og batteristørrelsene diskutert. I tillegg diskuteres mulig framtidig ladebehov for elektriske kjøretøy, og hvordan framtidig effektbehov i mikronettet kan bli i forhold til dagens simulerte effektbehov. Det konkluderes med at en batteriinvestering ikke er lønnsom med dagens oppgitte pris på 6 600 kr/kWh. Prisen per kWh må reduseres til å bli maksimalt 5 158 kr/kWh for at investeringen skal bli lønnsom med et 274 kWh batteri. Fra pristrendene presentert i teorien skal det finnes billige nok batteri til at prosjektet blir lønnsomt. Det er derimot ingen garanti for at batteriet har de samme spesifikasjonene og kvalitet som med dagens leverandør. Disse faktorene påvirker også lønnsomheten. Dersom det er ønskelig å undersøke hvordan store batteribanker bør og kan håndteres i fremtiden, kan det i dag investeres i et større batteri enn 274 kWh. TrønderEnergi må evaluere det økonomiske tapet med en større investering i dag opp mot fremtidig markedsverdi.The thesis deals with a microgrid at Brattørkaia in Trondheim with the four power customers Brattørkaia 15, 16 and 17a, an electric bus charger, and the power requirement in a parking basement under Brattørkaia 16 and 17a. The task will focus on how a battery is used for peak shaving, and various usage methods and sizes of a lithium-ion battery. Throughout the task, separate calculations are made on the technical and economic aspects, and the environmental aspect of the project is briefly assessed. Profitability is generally an important factor in the task. The task is limited to four battery sizes, four usage methods of the batteries, and three “charging cases” for the power consumption of the electric vehicle chargers. As of today, no exemption has been granted to construct the microgrid, but in this assignment the financial outcome is considered if an exemption is granted. It is then assumed free power flow within the microgrid; the cost distribution within the microgrid has not been assessed. The result presents the technical and economic analyzes separately for all surveys. These involve cost savings in microgrid merging, how a battery can be used for peak shaving, and how different battery sizes can be used in the microgrid. Profitability is generally assessed on the basis of the project’s present value, and the results also presents solutions to increase profitability. The results show that the construction of the microgrid will result in an annual saving for the four customers in the microgrid. The best method of use for the battery in the case of excess energy is to first charge with solar power, and then sell up to 100 kW to the regional grid. After peak shaving is finished for the day, the battery is fully discharged before it is recharged at night with cheaper power. The results also show that a battery investment is not profitable given the current purchase price. With price trends from today’s battery market it should be possible to find cheaper batteries on the market both today and in the future, which can give the project a positive present value. In the discussion the advantages and disadvantages of the battery investment, methods of use and battery sizes is accounted for. In addition, possible future charging requirements for electric vehicles are discussed. It is concluded that a battery investment is not profitable with today’s stated price of 6,600 NOK/kWh. The price per kWh must be reduced to a maximum of 5,158 NOK/kWh for the investment to be profitable with a battery of 274 kWh capacity. From the price trends presented in theory, batteries should be cheap enough to make the project profitable. However, there is no guarantee that the battery has the same specifications and quality as with today’s supplier. These factors also affect profitability. If it is desired to investigate the handeling of large battery banks in the future, it can be invested in a larger battery than 274 kWh today. TrønderEnergi must evaluate the financial loss of a larger battery bank today with the market value of the achieved knowledge

Automated Negotiation in Many-to-Many Markets for Imperfectly Substitutable Goods

In this paper, we present an agent which is able to negotiate the buying and selling of imperfectly sustitutable goods in a double auction style market. Two goods are said to be imperfectly substitutable if a buyer can use either of them, but prefers one over the other. For example, an electronics manufacturer using a RAM chip can use many suppliers to do this but may be willing to pay a premium for components with a lower failure rate. We give a formal description of a double-auction style market mechanism for trading such goods, and define the (classical) equilibrium in such an environment. We present the IS-ZIP agent, which is a generalisation of the ZIP agent for double auctions of Cli# and Bruten [3]. It is able to participate in our double auction environment to make purchases or sales of imperfectly substitutable goods. We demonstrate that, when trading a single good, it is equivalent to Preist and van Tol&apos;s modification of the ZIP agent [11]. We describe experiments where a group of IS-ZIP agents with di#erent valuations trade repeatedly, and demonstrate that they rapidly converge to our predicted equilibrium. We conclude by relating our work to that of others, particulary work dealing with multi-attribute negotiation, and discussing extensions