| 1. |
- Andersson, Christer, et al.
(author)
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Sealed bid auctions versus ascending bid auctions: an experimental study
- 2012
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In: Review of Economic Design. - : Springer Science and Business Media LLC. - 1434-4742 .- 1434-4750. ; 17, s. 1-16
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Journal article (peer-reviewed)abstract
- This paper considers two multi-item auction formats (ascending and sealed bid) which both identify the minimum Walrasian equilibrium prices and where truthful preference revelation constitutes an equilibrium. Even though these auction formats share many theoretical properties, there are behavioral aspects that are not easily captured. To explore this issue in more detail, this paper experimentally investigates what role the design of the auction format has for its outcome. The results suggest that the sealed bid mechanism performs weakly better in all of the investigated measures (consistent reporting, efficiency etc.). In addition, we find that the performance of the ascending auction is increasing over time, whereas the sealed bid auction shows no such tendency.
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| 2. |
- Andersson, Tommy, et al.
(author)
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An Empirical Investigation of Efficiency and Price Uniformity in Competing Auctions
- 2012
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In: Economics Letters. - : Elsevier BV. - 0165-1765. ; 116:1, s. 99-101
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Journal article (peer-reviewed)abstract
- Abstract in Undetermined This paper investigates hypotheses related to efficiency and price uniformity in online competing auctions based on two theoretical predictions from Peters and Severinov [Peters, M., Severinov, S., 2006. Internet auctions with many traders. Journal of Economic Theory 130, 220–245]. The investigation is conducted using a large and ideal data set for online competing train ticket auctions, and the findings support the theoretical predictions in large parts.
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| 3. |
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| 4. |
- Andersson, Ola, et al.
(author)
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Decomposing the Afternoon Effect: An Empirical Investigation of Sequential Train Ticket Auctions
- 2015
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Other publication (other academic/artistic)abstract
- The afternoon effect, i.e., that prices in a sequence of auctions with identical items are decreasing with the order in which the auctions are terminated, is a frequently observed phenomenon in empirical auction studies. Using an unsurpassed amount of data from sequential online train ticket auctions, we investigate two hitherto unexplored dimensions inherent in sequential auctions, namely, the timing of auction ends and the presentation order of the auctions in a sequence. We find that both these dimensions are important for price formation in sequential auctions, but even when controlling for them, a sizable afternoon effect remains.
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| 5. |
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| 6. |
- Andersson, Tommy, et al.
(author)
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Properties of the DGS-Auction Algorithm
- 2012
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In: Computational Economics. - : Springer Science and Business Media LLC. - 0927-7099 .- 1572-9974. ; 39:2, s. 113-133
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Journal article (peer-reviewed)abstract
- This paper investigates algorithmic properties and overall performance of the exact auction algorithm in Demange, Gale and Sotomayor (J. Polit. Economy 94: 863-872, 1986) or DGS for short. This task is achieved by interpreting DGS as a graph and by conducting a large number of computer simulations. The crucial step in DGS is when the auctioneer selects a so-called minimal overdemanded set of items because the specific selection may affect a number of performance measures such as the number of iterations and the ratio of elicited preferences. The computational results show that (i) DGS graphs are typically large even for relatively small numbers of bidders and items, (ii) DGS converges slowly and (iii) DGS performs well in terms of preference elicitation. The paper also demonstrates that the modification to DGS based on the Ford-Fulkerson algorithm outperforms all investigated rules for selecting a minimal overdemanded set of items in DGS both in terms of termination speed and preference elicitation.
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| 7. |
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| 8. |
- Andersson, Tommy, et al.
(author)
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Timing and presentation effects in sequential auctions
- 2017
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In: Journal of Mechanism and Institution Design. - : The Society for the Promotion of Mechanism and Institution Design. - 2399-844X .- 2399-8458. ; 2:1, s. 39-55
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Journal article (peer-reviewed)abstract
- This paper investigates two hitherto unexplored dimensions inherent in online sequential auctions, namely, how the time elapsed between the end of an auction and the end of the next one and the order of presentation on the website affect prices. Using a state-of-the-art-dataset on train-ticket auctions with a particular institutional design feature that enables a causal interpretation of these dimensions, it is demonstrated that both dimensions have a significant impact on price formation in sequential auctions.
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| 9. |
- Ghosheh, Nidal, 1975-, et al.
(author)
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Human Pluripotent Stem Cell-Derived Hepatocytes Show Higher Transcriptional Correlation with Adult Liver Tissue than with Fetal Liver Tissue
- 2020
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In: ACS Omega. - : American Chemical Society (ACS). - 2470-1343. ; 5:10, s. 4816-4827
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Journal article (peer-reviewed)abstract
- Human pluripotent stem cell-derived hepatocytes (hPSC-HEP) display many properties of mature hepatocytes, including expression of important genes of the drug metabolizing machinery, glycogen storage, and production of multiple serum proteins. To this date, hPSC-HEP do not, however, fully recapitulate the complete functionality of in vivo mature hepatocytes. In this study, we applied versatile bioinformatic algorithms, including functional annotation and pathway enrichment analyses, transcription factor binding-site enrichment, and similarity and correlation analyses, to datasets collected from different stages during hPSC-HEP differentiation and compared these to developmental stages and tissues from fetal and adult human liver. Our results demonstrate a high level of similarity between the in vitro differentiation of hPSC-HEP and in vivo hepatogenesis. Importantly, the transcriptional correlation of hPSC-HEP with adult liver (AL) tissues was higher than with fetal liver (FL) tissues (0.83 and 0.70, respectively). Functional data revealed mature features of hPSC-HEP including cytochrome P450 enzymes activities and albumin secretion. Moreover, hPSC-HEP showed expression of many genes involved in drug absorption, distribution, metabolism, and excretion. Despite the high similarities observed, we identified differences of specific pathways and regulatory players by analyzing the gene expression between hPSC-HEP and AL. These findings will aid future intervention and improvement of in vitro hepatocyte differentiation protocol in order to generate hepatocytes displaying the complete functionality of mature hepatocytes. Finally, on the transcriptional level, our results show stronger correlation and higher similarity of hPSC-HEP to AL than to FL. In addition, potential targets for further functional improvement of hPSC-HEP were also identified.
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| 10. |
- Lång, P, et al.
(author)
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Expression and secretion of the novel adipokine tartrate-resistant acid phosphatase from adipose tissues of obese and lean women
- 2011
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In: International Journal of Obesity. - : Springer Science and Business Media LLC. - 0307-0565 .- 1476-5497. ; 35:12, s. 1502-1510
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Journal article (peer-reviewed)abstract
- Objective: Tartrate-resistant acid phosphatase (TRAP) expressed by adipose tissue macrophages (ATMs) induces mice obesity and human adipocyte differentiation in vitro. This study aimed to investigate whether TRAP was secreted differently from human obese versus lean adipose tissues and to identify the cellular source of adipose tissue TRAP.Design: Subcutaneous adipose tissues obtained from healthy subjects. Enzyme-linked immunosorbent assays (ELISAs) for total (5a+5b) and cleaved TRAP (5b) were used. TRAP secretion was determined in adipose tissue biopsies, and mRNA expression was studied in cell types isolated from the same.Subjects: Results of 24 lean and 24 obese women (in vitro) and 8 subjects (in vivo) were compared. The main outcome measurements were TRAP expression and secretion in vitro and in vivo.Results: In-house total TRAP ELISA showed high sensitivity and a coefficient of variance of 11%. Adipose secretion of total TRAP was linear in vitro with time and was evident in vivo. Total TRAP secretion in vitro was similar in lean and obese women expressed per unit weight of the adipose tissue but correlated positively with the number/size of adipocytes (P≤0.01) and with adipose secretion of tumor necrosis factor-α and interleukin-6 (P<0.01). TRAP 5b was not secreted from the adipose tissue. ATMs displayed highest cellular expression of TRAP mRNA in adipose tissue cells derived from lean or obese women.Conclusions: TRAP is a novel human adipokine produced by macrophages and secreted from the subcutaneous adipose tissue in vivo and in vitro. Secretion is linked to the size and number of adipocytes, as well as to concomitant secretion of inflammatory mediators, suggesting that TRAP is involved in fat accumulation and adipose inflammation. International Journal of Obesity advance online publication, 8 March 2011; doi:10.1038/ijo.2011.17.
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