319 research outputs found

    Multiple openings and competitiveness of forward markets: experimental evidence

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    We test the competition enhancing effect of selling forward in experimental Cournot duopoly and quadropoly with multiple forward markets. We find that having two forward periods yields competitive outcomes and that the results are very close to the predicted theoretical results for both quantity setting duopolies and quadropolies. Our experiments lend strong support to the hypothesis that forward markets are competition enhancing. We then test a new market that allows for endogenously determined indefinitely many forward periods that only close when sellers coordinate on selling a zero amount in a forward market. We find that the outcomes under an endogenous close rule are also very competitive. These results hold for both duopolies and quadropolies

    Trustors' disregard for trustees deciding quickly or slowly in three experiments with time constraints

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    Many decisions in the economic and social domain are made under time constraints, be it under time pressure or forced delay. Requiring individuals to decide quickly or slowly often elicit different responses. Time pressure has been associated with inefficiency in market settings and market regulation often requires individuals to delay their decisions via cooling-off periods. Yet, recent research suggests that people who make reflective decisions are met with distrust. If this extends to external time constraints, then forcing individuals to delay their decisions may be counterproductive in scenarios where trust considerations are important, such as in market and organizational design. In three Trust Game experiments (total number of participants = 1872), including within- and between subjects designs, we test whether individuals trust (more) someone who is forced to respond quickly (intuitively) or slowly (reflectively). We find that trustors do not adjust their behavior (or their beliefs) to the trustee’s time conditions. This seems to be an appropriate response because time constraints do not affect trustees’ behavior, at least when the game decisions are binary (trust vs. don’t trust; reciprocate vs. don’t reciprocate) and therefore mistakes cannot explain choices. Thus, delayed decisions per se do not seem to elicit distust

    To trust or not to trust: cognitive reflection in trust game

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    We present results from two studies that show a positive relation between cognitive reflection and trusting behavior, but no significant relation with trustworthy behavior. Our finding holds regardless of individual distributional social preferences and risk aversion. Our results add to a growing body of literature that illustrates the role of cognitive ability in helping explain outcomes in economic experiments

    Mechanism Design for Perturbation Stable Combinatorial Auctions

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    Motivated by recent research on combinatorial markets with endowed valuations by (Babaioff et al., EC 2018) and (Ezra et al., EC 2020), we introduce a notion of perturbation stability in Combinatorial Auctions (CAs) and study the extend to which stability helps in social welfare maximization and mechanism design. A CA is γ-stable\gamma\textit{-stable} if the optimal solution is resilient to inflation, by a factor of γ1\gamma \geq 1, of any bidder's valuation for any single item. On the positive side, we show how to compute efficiently an optimal allocation for 2-stable subadditive valuations and that a Walrasian equilibrium exists for 2-stable submodular valuations. Moreover, we show that a Parallel 2nd Price Auction (P2A) followed by a demand query for each bidder is truthful for general subadditive valuations and results in the optimal allocation for 2-stable submodular valuations. To highlight the challenges behind optimization and mechanism design for stable CAs, we show that a Walrasian equilibrium may not exist for γ\gamma-stable XOS valuations for any γ\gamma, that a polynomial-time approximation scheme does not exist for (2ϵ)(2-\epsilon)-stable submodular valuations, and that any DSIC mechanism that computes the optimal allocation for stable CAs and does not use demand queries must use exponentially many value queries. We conclude with analyzing the Price of Anarchy of P2A and Parallel 1st Price Auctions (P1A) for CAs with stable submodular and XOS valuations. Our results indicate that the quality of equilibria of simple non-truthful auctions improves only for γ\gamma-stable instances with γ3\gamma \geq 3

    How do markets manage water resources? An experiment

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    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

    Lenalidomide treatment and prognostic markers in relapsed or refractory chronic lymphocytic leukemia: data from the prospective, multicenter phase-II CLL-009 trial

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    Efficacy of lenalidomide was investigated in 103 patients with relapsed/refractory chronic lymphocytic leukemia (CLL) treated on the prospective, multicenter randomized phase-II CLL-009 trial. Interphase cytogenetic and mutational analyses identified TP53 mutations, unmutated IGHV, or del(17p) in 36/96 (37.5%), 68/88 (77.3%) or 22/92 (23.9%) patients. The overall response rate (ORR) was 40.4% (42/104). ORRs were similar irrespective of TP53 mutation (36.1% (13/36) vs 43.3% (26/60) for patients with vs without mutation) or IGHV mutation status (45.0% (9/20) vs 39.1% (27/68)); however, patients with del(17p) had lower ORRs than those without del(17p) (21.7% (5/22) vs 47.1% (33/70); P=0.049). No significant differences in progression-free survival and overall survival (OS) were observed when comparing subgroups defined by the presence or absence of high-risk genetic characteristics. In multivariate analyses, only multiple prior therapies (greater than or equal to3 lines) significantly impacted outcomes (median OS: 21.2 months vs not reached; P=0.019). This analysis indicates that lenalidomide is active in patients with relapsed/refractory CLL with unfavorable genetic profiles, including TP53 inactivation or unmutated IGHV. (ClinicalTrials.gov identifier: NCT00963105)

    Somatic MED12 mutations are associated with poor prognosis markers in chronic lymphocytic leukemia

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    Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. We performed systematic database search and identified highly specific MED12 mutations in CLL patients. To study this further, we collected three independent sample series comprising over 700 CLL samples and screened MED12 exons 1 and 2 by direct sequencing. Mutations were identified at significant frequency in all three series with a combined mutation frequency of 5.2% (37/709). Positive mutation status was found to be associated with unmutated IGHV and ZAP70 expression, which are well-known poor prognosis markers in CLL. Our results recognize CLL as the first extrauterine cancer type where 5'terminus of MED12 is mutated at significant frequency. Functional analyses have shown that these mutations lead to dissociation of Cyclin C-CDK8/19 from the core Mediator and to the loss of Mediator-associated CDK kinase activity. Additional studies on the role of MED12 mutation status as a putative prognostic factor as well as mutations' exact tumorigenic mechanism in CLL are warranted.Peer reviewe
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