Arbitrages and Arrow-Debreu Prices

The goal of this work is to check that there are no arbitrage opportunities in the CBOE market for S&P500 options and to extract from these options’ quotes the state-price density consistent with the Merton model. The structure of the article is as follows: in Section 2 we examine the relations between arbitrages and Arrow-Debreu prices; in Section 3 we consider two models which seem to be consistent with the market prices of index options: the CEV model and the Merton model; finally, in Section 4 we estimate the state-price density consistent with the Merton-Geske model. Some conclusions follow.state-price density, index options, Merton-Geske model

The effect of mafia on public transfers

Organized crime is a worldwide, widespread phenomenon, which affects developing as well as developed countries, and entails deep economic and social consequences. The purpose of this study is to enhance our understanding of organized crime activities. By using an innovative data set on Sicilian mafia activity available at municipality level, we test whether firms located in municipalities with mafia-related crimes obtain more public subsidies. In order to deal with the endogeneity of the relationship, we explore the origins of mafia. We instrument current mafia activity with exogenous historical and geographical shifters of land productivity, i.e. rainfall in the XIX century and geographical features at municipality level. We provide evidence that the presence of mafia affects the allocation of public transfers: municipalities with mafia activity receive larger public funding. The estimated impact of mafia is also economically relevant and equals one standard deviation of the dependent variable. According to our estimates the presence of mafia increases the total amounts of funds by about 35% on average. A series of robustness checks confirms the above findings.organized crime, public transfers

Deleveraging CAPM: Asset Betas vs. Equity Betas

The classic estimates of CAPM equity betas are notoriously unstable. We suppose that this is mainly due to changes of firm\u2019s leverage over time. In order to take leverage into account, we propose a new approach where asset correlations among firms are pairwise constant, while equity correlations depend on the stochastic evolution of firms\u2019 asset values

Telecracy: Testing for Channels of Persuasion

We consider the long-lived slant towards Berlusconi in political information on Italian television (TV ). We exploit a shock to the slanted exposure of viewers: idiosyncratic deadlines to switch to digital TV from 2008 to 2012, which increased the number of freeview channels tenfold. The switch caused a drop in the vote share of Berlusconi’s coalition by between 5.5 and 7.5 percentage points. The effect was stronger in towns with older and less educated voters. At least 20 percent of digital users changed their voting behavior after the introduction of digital TV. Our evidence is consistent with the existence of persuasion- biased viewers

Mimicking Credit Ratings by a Perpetual-Debt Structural Model

In this paper, we outline the general lines of a structural model that is based on the Leland model (1994), but differs from its assumptions about the tax regime. In the revised model, which we call the Perpetual-Debt Structural Model (PDSM), stocks are equivalent to a portfolio that contains a perpetual American option to default. This paper offers a first empirical test of the model. Essentially, the question is: \u201cIs the PDSM sufficiently flexible to give default probabilities consistent with those historically estimated by Moody\u2019s?\u201d. As we will see, the answer is positive. The paper contains a simple firm-level application. The PDSM risk indicators have been used to define the \u201cmarket rating\u201d of Deutsche Bank

Previdenza complementare: proiezioni di lungo periodo nell’ottica dell’analisi di sostenibilità

5noopenopenFersini, Paola; Barone, Gaia; Forte, Salvatore; Olivieri, Gennaro; Melisi, GiuseppeFersini, Paola; Barone, Gaia; Forte, Salvatore; Olivieri, Gennaro; Melisi, Giusepp

The antidepressant fluoxetine acts on energy balance and leptin sensitivity via BDNF

Leptin and Brain Derived Neurotrophic Factor (BDNF) pathways are critical players in body weight homeostasis. Noninvasive treatments like environmental stimulation are able to increase response to leptin and induce BDNF expression in the brain. Emerging evidences point to the antidepressant selective serotonin reuptake inhibitor Fluoxetine (FLX) as a drug with effects similar to environmental stimulation. FLX is known to impact on body weight, with mechanisms yet to be elucidated. We herein asked whether FLX affects energy balance, the leptin system and BDNF function. Adult lean male mice chronically treated with FLX showed reduced weight gain, higher energy expenditure, increased sensitivity to acute leptin, increased hypothalamic BDNF expression, associated to changes in white adipose tissue expression typical of "brownization". In the Ntrk2tm1Ddg/J model, carrying a mutation in the BDNF receptor Tyrosine kinase B (TrkB), these effects are partially or totally reversed. Wild type obese mice treated with FLX showed reduced weight gain, increased energy output, and differently from untreated obese mice, a preserved acute response to leptin in terms of activation of the intracellular leptin transducer STAT3. In conclusion, FLX impacts on energy balance and induces leptin sensitivity and an intact TrkB function is required for these effects to take place

The ALLgorithMM: How to define the hemodilution of bone marrow samples in lymphoproliferative diseases

IntroductionMinimal residual disease (MRD) is commonly assessed in bone marrow (BM) aspirate. However, sample quality can impair the MRD measurement, leading to underestimated residual cells and to false negative results. To define a reliable and reproducible method for the assessment of BM hemodilution, several flow cytometry (FC) strategies for hemodilution evaluation have been compared. MethodsFor each BM sample, cells populations with a well-known distribution in BM and peripheral blood - e.g., mast cells (MC), immature (IG) and mature granulocytes (N) - have been studied by FC and quantified alongside the BM differential count. ResultsThe frequencies of cells' populations were correlated to the IG/N ratio, highlighting a mild correlation with MCs and erythroblasts (R=0.25 and R=0.38 respectively, with p-value=0.0006 and 0.0000052), whereas no significant correlation was found with B or T-cells. The mild correlation between IG/N, erythroblasts and MCs supported the combined use of these parameters to evaluate BM hemodilution, hence the optimization of the ALLgorithMM. Once validated, the ALLgorithMM was employed to evaluate the dilution status of BM samples in the context of MRD assessment. Overall, we found that 32% of FC and 52% of Next Generation Sequencing (NGS) analyses were MRD negative in samples resulted hemodiluted (HD) or at least mildly hemodiluted (mHD). ConclusionsThe high frequency of MRD-negative results in both HD and mHD samples implies the presence of possible false negative MRD measurements, impairing the correct assessment of patients' response to therapy and highlighs the importance to evaluate BM hemodilution

The association between insight and depressive symptoms in schizophrenia: Undirected and Bayesian network analyses

Background. Greater levels of insight may be linked with depressive symptoms among patients with schizophrenia, however, it would be useful to characterize this association at symptom-level, in order to inform research on interventions. Methods. Data on depressive symptoms (Calgary Depression Scale for Schizophrenia) and insight (G12 item from the Positive and Negative Syndrome Scale) were obtained from 921 community-dwelling, clinically-stable individuals with a DSM-IV diagnosis of schizophrenia, recruited in a nationwide multicenter study. Network analysis was used to explore the most relevant connections between insight and depressive symptoms, including potential confounders in the model (neurocognitive and social-cognitive functioning, positive, negative and disorganization symptoms, extrapyramidal symptoms, hostility, internalized stigma, and perceived discrimination). Bayesian network analysis was used to estimate a directed acyclic graph (DAG) while investigating the most likely direction of the putative causal association between insight and depression. Results. After adjusting for confounders, better levels of insight were associated with greater self-depreciation, pathological guilt, morning depression and suicidal ideation. No difference in global network structure was detected for socioeconomic status, service engagement or illness severity. The DAG confirmed the presence of an association between greater insight and self-depreciation, suggesting the more probable causal direction was from insight to depressive symptoms. Conclusions. In schizophrenia, better levels of insight may cause self-depreciation and, possibly, other depressive symptoms. Person-centered and narrative psychotherapeutic approaches may be particularly fit to improve patient insight without dampening self-esteem

How future surgery will benefit from SARS-COV-2-related measures: a SPIGC survey conveying the perspective of Italian surgeons

COVID-19 negatively affected surgical activity, but the potential benefits resulting from adopted measures remain unclear. The aim of this study was to evaluate the change in surgical activity and potential benefit from COVID-19 measures in perspective of Italian surgeons on behalf of SPIGC. A nationwide online survey on surgical practice before, during, and after COVID-19 pandemic was conducted in March-April 2022 (NCT:05323851). Effects of COVID-19 hospital-related measures on surgical patients' management and personal professional development across surgical specialties were explored. Data on demographics, pre-operative/peri-operative/post-operative management, and professional development were collected. Outcomes were matched with the corresponding volume. Four hundred and seventy-three respondents were included in final analysis across 14 surgical specialties. Since SARS-CoV-2 pandemic, application of telematic consultations (4.1% vs. 21.6%; p < 0.0001) and diagnostic evaluations (16.4% vs. 42.2%; p < 0.0001) increased. Elective surgical activities significantly reduced and surgeons opted more frequently for conservative management with a possible indication for elective (26.3% vs. 35.7%; p < 0.0001) or urgent (20.4% vs. 38.5%; p < 0.0001) surgery. All new COVID-related measures are perceived to be maintained in the future. Surgeons' personal education online increased from 12.6% (pre-COVID) to 86.6% (post-COVID; p < 0.0001). Online educational activities are considered a beneficial effect from COVID pandemic (56.4%). COVID-19 had a great impact on surgical specialties, with significant reduction of operation volume. However, some forced changes turned out to be benefits. Isolation measures pushed the use of telemedicine and telemetric devices for outpatient practice and favored communication for educational purposes and surgeon-patient/family communication. From the Italian surgeons' perspective, COVID-related measures will continue to influence future surgical clinical practice