130 research outputs found

    No-Trade in the Laboratory

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    We test the no-trade theorem in a laboratory nancial market where subjects can trade an asset whose value is unknown. Subjects receive clues on the asset value and then set a bid and an ask at which they are willing to buy or to sell from the other participants. In treatments with no gains from trade, theory predicts no trading activity, whereas, in treatments with gains, trade becomes theoretically possible. Our experimental results show that subjects fail to reach the no-trade equilibrium by pure introspection, but they learn to approach it over time, through market feedback and learning.

    No-Trade in the Laboratory

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    We test the no-trade theorem in a laboratory financial market where subjects can trade an asset whose value is unknown. Subjects receive clues on the asset value and then set a bid and an ask at which they are willing to buy or to sell from the other participants. In treatments with no gains from trade, theory predicts no trading activity, whereas, in treatments with gains, trade becomes theoretically possible. Our experimental results show that subjects fail to reach the no-trade equilibrium by pure introspection, but they learn to approach it over time,through market feedback and learning.no-trade theorem, experiment

    Cognitive Ability, Cognitive Aging, and Debt Accumulation

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    In the past few decades, financial products target to consumers have become increasingly complex and recent evidence suggests that older adults are entering retirement with more debt than previous generations. We examine how cognitive ability is related to debt burdens among older adults and whether this relationship has changed over time with the increasingly complex financial landscape. Using data from the Health and Retirement Study spanning 1998 to 2014, we find that cognitive ability is an important predictor of debt burdens in older age and that, in more complex financial environments, individuals with higher cognitive ability have taken on higher debt levels than individuals with lower cognitive ability. In a complementary analysis using data from 2015 to 2019 drawn from the Understanding America Study, we find similar results and evidence that the relationship between cognitive ability and debt exposure is driven by financial sophistication. Our findings are broadly inconsistent with financial intermediaries pushing increasingly complicated financial products onto unsophisticated borrowers. However, we find that even higher cognitive ability individuals may have difficulty managing their debt burdens in more complex environments – they hold less total wealth, less liquid wealth, and are more likely to have debt levels that exceed half their assets than their counterparts prior to the expansion in complexity. All told, we find that individuals with higher cognitive ability disproportionately increased their debt burdens during the increase in financial product complexity, and that subsequently they were more financially fragile than similar individuals in previous cohorts.U.S. Social Security Administration, RDR18000002-02, UM20-11http://deepblue.lib.umich.edu/bitstream/2027.42/168222/1/wp411.pdfDescription of wp411.pdf : working paperSEL

    Investment Decisions in Retirement: The Role of Subjective Expectations

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    Working Paper: WP 2012-274The rapid transition from defined benefit (DB) pension plans to defined contribution (DC) plans has a potential benefit of offering pension holders greater control over how their pension accumulations are invested. If pension holders are willing to take some risk, investments in the stock market could increase their economic preparation for retirement, and, indeed, economic theory as well as the typical advice of financial advisors calls for stock market investments. Yet, the rate of stock holding is much below what theory suggests it should be, undoing any benefit associated with the greater control coming from DC plans. The leading explanations for this under-investing include excessive risk aversion, costs of entry, and misperceptions about possible returns in the stock market. We show that excessive risk aversion is not able to account for the low fraction of stock holding. However, a model with heterogeneous subjective expectations about stock market returns is able to account for low stock market participation, and tracks the share of risky assets conditional on participation reasonably well. Based on the model with subjective expectations, we estimate a welfare loss of up to 12% compared to investment under rational expectations, if actual returns follow the same distribution as in the past 50 years. The policy implication is that there is considerable scope for welfare improvement as a result of consumer education regarding stock market returns. However, the welfare loss is much smaller if individuals are not very risk averse or if actual returns follow the same distribution as in the past 10 years.Social Security Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/94534/1/wp274.pd

    Labor Force Transitions at Older Ages: The Roles of Work Environment and Personality

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    Besides compensation and financial incentives, several other work-related factors may affect individual retirement decisions. Specifically, job characteristics such as autonomy, skill variety, task significance and difficulty, stress and physical demands, peer pressure and relations with co-workers, play a crucial role in determining psychological commitment to work at older ages. While financial preparedness for retirement and health shocks are often cited as main predictors of the choice to exit the labor force, there exists relatively little research documenting the extent to which the work environment itself and its interaction with economic variables influence retirement decisions. We document that job characteristics are associated with labor force transitions at older ages, in particular transitions to retirement and part-time employment. Additionally, we show that while personality traits do not directly drive labor force transitions, the effect of job characteristics on labor supply outcomes varies with the “intensity” of personality traits. We also document that job characteristics themselves are strongly related to personality traits. This suggests that, depending on their personality, individuals may select into specific jobs, whose characteristics ultimately shape their retirement paths.Social Security Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/102270/1/wp295.pd

    Challenging Scenarios and Debated Indications for Laparoscopic Liver Resections for Hepatocellular Carcinoma

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    Simple Summary Minimally invasive liver resections are nowadays performed worldwide for both benign and malignant lesions. Good short-term and safe long-term outcomes have been reported. Despite this growing implementation of the technique, challenging scenarios and debated indications still exist. There is currently a lack of high-quality evidence regarding minimally invasive liver resections in portal hypertension, advanced cirrhosis, lesions in the posterosuperior segments and large and recurrent tumors. Laparoscopic liver resections (LLRs) have been increasingly adopted for the treatment of hepatocellular carcinoma (HCC), with safe short- and long-term outcomes reported worldwide. Despite this, lesions in the posterosuperior segments, large and recurrent tumors, portal hypertension, and advanced cirrhosis currently represent challenging scenarios in which the safety and efficacy of the laparoscopic approach are still controversial. In this systematic review, we pooled the available evidence on the short-term outcomes of LLRs for HCC in challenging clinical scenarios. All randomized and non-randomized studies reporting LLRs for HCC in the above-mentioned settings were included. The literature search was run in the Scopus, WoS, and Pubmed databases. Case reports, reviews, meta-analyses, studies including fewer than 10 patients, non-English language studies, and studies analyzing histology other than HCC were excluded. From 566 articles, 36 studies dated between 2006 and 2022 fulfilled the selection criteria and were included in the analysis. A total of 1859 patients were included, of whom 156 had advanced cirrhosis, 194 had portal hypertension, 436 had large HCCs, 477 had lesions located in the posterosuperior segments, and 596 had recurrent HCCs. Overall, the conversion rate ranged between 4.6% and 15.5%. Mortality and morbidity ranged between 0.0% and 5.1%, and 18.6% and 34.6%, respectively. Full results according to subgroups are described in the study. Advanced cirrhosis and portal hypertension, large and recurrent tumors, and lesions located in the posterosuperior segments are challenging clinical scenarios that should be carefully approached by laparoscopy. Safe short-term outcomes can be achieved provided experienced surgeons and high-volume centers

    Evolution of Bariatric Surgery in Italy in the Last 11 Years: Data from the SICOB Yearly National Survey

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    Background: Bariatric surgery (BS) is a relatively novel surgical field and is in continuous expansion and evolution. Purpose: Aim of this study was to report changes in Italian surgical practice in the last decade. Methods: The Società Italiana di Chirurgia dell'Obesità (SICOB) conducted annual surveys to cense activity of SICOB centers between 2011 and 2021. Primary outcome was to detect differences in frequency of performance of adjustable gastric banding (AGB), sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), one anastomosis gastric bypass (OAGB), bilio-pancreatic diversion (BPD), and gastric plication (GP). Secondary outcome was to detect differences in performance of main non-malabsorptive procedures (AGB + SG) and overall bypass procedures (RYGB + OAGB). Geographical differences were also investigated. Results: Median response rate was 92%. AGB declined from 36% of procedures in 2011 to 5% in 2021 (p < 0.0001). SG increased from 30% in 2011 to 55% in 2021 (p < 0.0001). RYGB declined from 25 to 12% of procedures (p < 0.0001). OAGB rose from 0% of procedures in 2011 to 15% in 2021 (p < 0.0001). BPD underwent decrease from 6.2 to 0.2% in 2011 and 2021, respectively (p < 0.0001). Main non-malabsorptive procedures significantly decreased while overall bypass procedures remained stable. There were significant differences among regions in performance of SG, RYGB, and OAGB. Conclusions: BS in Italy evolved significantly during the past 10 years. AGB underwent a decline, as did BPD and GP which are disappearing and RYGB which is giving way to OAGB. The latter is rising and is the second most-performed procedure after SG which has been confirmed as the preferred procedure by Italian bariatric surgeons

    Colorectal cancer after bariatric surgery (Cric-Abs 2020): Sicob (Italian society of obesity surgery) endorsed national survey

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    Background The published colorectal cancer (CRC) outcomes after bariatric surgery (BS) are conflicting, with some anecdotal studies reporting increased risks. The present nationwide survey CRIC-ABS 2020 (Colo-Rectal Cancer Incidence-After Bariatric Surgery-2020), endorsed by the Italian Society of Obesity Surgery (SICOB), aims to report its incidence in Italy after BS, comparing the two commonest laparoscopic procedures-Sleeve Gastrectomy (SG) and Roux-en-Y gastric bypass (GBP). Methods Two online questionnaires-first having 11 questions on SG/GBP frequency with a follow-up of 5-10 years, and the second containing 15 questions on CRC incidence and management, were administered to 53 referral bariatric, high volume centers. A standardized incidence ratio (SIR-a ratio of the observed number of cases to the expected number) with 95% confidence intervals (CI) was calculated along with CRC incidence risk computation for baseline characteristics. Results Data for 20,571 patients from 34 (63%) centers between 2010 and 2015 were collected, of which 14,431 had SG (70%) and 6140 GBP (30%). 22 patients (0.10%, mean age = 53 +/- 12 years, 13 males), SG: 12 and GBP: 10, developed CRC after 4.3 +/- 2.3 years. Overall incidence was higher among males for both groups (SG: 0.15% vs 0.05%; GBP: 0.35% vs 0.09%) and the GBP cohort having slightly older patients. The right colon was most affected (n = 13) and SIR categorized/sex had fewer values &lt; 1, except for GBP males (SIR = 1.07). Conclusion Low CRC incidence after BS at 10 years (0.10%), and no difference between procedures was seen, suggesting that BS does not trigger the neoplasm development
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