Investor Behaviour Facing Risk : Neurofinance and Financial Crises

Cette thèse étudie le comportement des investisseurs au travers de leur performance et de leurs attentes durant les crises financières de 2008-2011 et de leurs croyances. Elle se compose de trois chapitres. Dans le premier chapitre, nous faisons une revue de la littérature existante sur la performance des investisseurs individuels, leur biais comportementaux et leurs préférences. Nous montrons les principales lacunes en termes de performance des investisseurs individuels ainsi que leurs principaux biais comportementaux. Nous mettons également en lumière l’apport des neurosciences dans la compréhension du comportement des investisseurs individuels. Dans le deuxième chapitre, nous étudions l’impact des crises financières de 2008-2011 sur la performance des investisseurs individuels et leurs attentes à l’égard de leurs intermédiaires financiers dans quatre différents pays : Allemagne, Belgique, Luxembourg, France. Nous établissons également une comparaison en fonction du niveau de richesse des investisseurs à l’intérieur de chaque pays mais aussi globalement. Nos données proviennent de questionnaires distribués à des gestionnaires d’actifs dans les plus grandes banques des pays pris en considération ainsi que des données de marché historiques pour chacun de ces pays. Nous montrons que les investisseurs les plus fortunés sont les moins réfractaires à la prise de risque que ce soit avant ou après les crises financières, quel que soit le pays pris en considération. Nous remarquons aussi que ces derniers adoptent les stratégies d’investissement les moins conservatrices. Enfin nous notons un important changement des attentes des investisseurs par rapport à leurs intermédiaires financiers, demandant plus de transparence et un meilleur service clientèle, quel que soit le niveau de richesse. Nous montrons enfin que ces attentes peuvent être contradictoires notamment chez les investisseurs les moins fortunés. Dans le troisième chapitre, nous fournissons un test expérimental sur la formation des croyances chez les investisseurs individuels d’après le modèle de Brunnermeier et Parker (2005). Nous utilisons à cet effet une expérimentation avec deux loteries identiques exceptées leur skewness. Nous montrons que les participants à cette expérimentation ressentent des émotions par anticipation une fois qu’ils ont pris connaissance de la loterie à laquelle ils vont jouer. Ces émotions se forment à partir de la deuxième minute d’attente et restent stables jusqu’à ce qu’ils prennent connaissance de leurs gains. Par ailleurs, ces émotions par anticipation sont aussi fortes que celles ressenties une fois leurs gains connus. Enfin nous montrons que les sujets participants à la loterie avec une skewness positive présente moins de capacité d’auto régulation que les autres sujets. Les émotions qu’ils ressentent sont plus fortes et plus persistantes que chez les autres.This thesis studies the investors behaviour through their performance and their expectations during the 2008-2011 financial crises as well as their beliefs formation. It consists of three chapters. In the first chapter, we review the literature on individual investors performance, their behavioural biases and their preferences. We highlight their lack of performance on financial markets and their main behavioural biases. We also exhibit the contribution of neurosciences in the understanding of the investor’s brain. In the second chapter, we study the impacts of the 2008-2011 financial crises on individual investors returns and their expectations towards their financial intermediaries in four different countries: Belgium, France, Germany, Luxembourg. We also consider investors differences regarding their endowment, inside each country and globally. Our dataset is extracted from questionnaires administered to asset managers in the main banks in the countries considered as well as historical market data for each country. We show that wealthier investors are less risk averse and their level of risk aversion has not changed with financial crises whatever the country considered. Furthermore, these wealthier investors adopt less conservative investment strategies than retail ones. We notice an important shift regarding the investors’ expectations towards their financial intermediaries, since the crises they ask for more transparency and more client services. We also show that these expectations may be contradictory a bit in retail investors. In the third chapter, we provide an experimental test of investors beliefs formations according to Brunnermeier and Parker model (2005). For this purpose, we use a two identical lotteries design except in terms of skewness. We show that participants to this experiment feel anticipatory emotions once they have learned the lottery they will play. These emotions are formed from the second waiting minute and remain stable until they learn their gains. Besides, anticipatory emotions are as strong as emotions felt once the payoffs known. Finally, we demonstrate that subjects participating in the positively skewed lottery exhibit less self-regulation than other subjects. Hence, their emotions are stronger and more persistent

Investor Behaviour Facing Risk : Neurofinance and Financial Crises

Cette thèse étudie le comportement des investisseurs au travers de leur performance et de leurs attentes durant les crises financières de 2008-2011 et de leurs croyances. Elle se compose de trois chapitres. Dans le premier chapitre, nous faisons une revue de la littérature existante sur la performance des investisseurs individuels, leur biais comportementaux et leurs préférences. Nous montrons les principales lacunes en termes de performance des investisseurs individuels ainsi que leurs principaux biais comportementaux. Nous mettons également en lumière l’apport des neurosciences dans la compréhension du comportement des investisseurs individuels. Dans le deuxième chapitre, nous étudions l’impact des crises financières de 2008-2011 sur la performance des investisseurs individuels et leurs attentes à l’égard de leurs intermédiaires financiers dans quatre différents pays : Allemagne, Belgique, Luxembourg, France. Nous établissons également une comparaison en fonction du niveau de richesse des investisseurs à l’intérieur de chaque pays mais aussi globalement. Nos données proviennent de questionnaires distribués à des gestionnaires d’actifs dans les plus grandes banques des pays pris en considération ainsi que des données de marché historiques pour chacun de ces pays. Nous montrons que les investisseurs les plus fortunés sont les moins réfractaires à la prise de risque que ce soit avant ou après les crises financières, quel que soit le pays pris en considération. Nous remarquons aussi que ces derniers adoptent les stratégies d’investissement les moins conservatrices. Enfin nous notons un important changement des attentes des investisseurs par rapport à leurs intermédiaires financiers, demandant plus de transparence et un meilleur service clientèle, quel que soit le niveau de richesse. Nous montrons enfin que ces attentes peuvent être contradictoires notamment chez les investisseurs les moins fortunés. Dans le troisième chapitre, nous fournissons un test expérimental sur la formation des croyances chez les investisseurs individuels d’après le modèle de Brunnermeier et Parker (2005). Nous utilisons à cet effet une expérimentation avec deux loteries identiques exceptées leur skewness. Nous montrons que les participants à cette expérimentation ressentent des émotions par anticipation une fois qu’ils ont pris connaissance de la loterie à laquelle ils vont jouer. Ces émotions se forment à partir de la deuxième minute d’attente et restent stables jusqu’à ce qu’ils prennent connaissance de leurs gains. Par ailleurs, ces émotions par anticipation sont aussi fortes que celles ressenties une fois leurs gains connus. Enfin nous montrons que les sujets participants à la loterie avec une skewness positive présente moins de capacité d’auto régulation que les autres sujets. Les émotions qu’ils ressentent sont plus fortes et plus persistantes que chez les autres.This thesis studies the investors behaviour through their performance and their expectations during the 2008-2011 financial crises as well as their beliefs formation. It consists of three chapters. In the first chapter, we review the literature on individual investors performance, their behavioural biases and their preferences. We highlight their lack of performance on financial markets and their main behavioural biases. We also exhibit the contribution of neurosciences in the understanding of the investor’s brain. In the second chapter, we study the impacts of the 2008-2011 financial crises on individual investors returns and their expectations towards their financial intermediaries in four different countries: Belgium, France, Germany, Luxembourg. We also consider investors differences regarding their endowment, inside each country and globally. Our dataset is extracted from questionnaires administered to asset managers in the main banks in the countries considered as well as historical market data for each country. We show that wealthier investors are less risk averse and their level of risk aversion has not changed with financial crises whatever the country considered. Furthermore, these wealthier investors adopt less conservative investment strategies than retail ones. We notice an important shift regarding the investors’ expectations towards their financial intermediaries, since the crises they ask for more transparency and more client services. We also show that these expectations may be contradictory a bit in retail investors. In the third chapter, we provide an experimental test of investors beliefs formations according to Brunnermeier and Parker model (2005). For this purpose, we use a two identical lotteries design except in terms of skewness. We show that participants to this experiment feel anticipatory emotions once they have learned the lottery they will play. These emotions are formed from the second waiting minute and remain stable until they learn their gains. Besides, anticipatory emotions are as strong as emotions felt once the payoffs known. Finally, we demonstrate that subjects participating in the positively skewed lottery exhibit less self-regulation than other subjects. Hence, their emotions are stronger and more persistent

A united statement of the global chiropractic research community against the pseudoscientific claim that chiropractic care boosts immunity.

BACKGROUND: In the midst of the coronavirus pandemic, the International Chiropractors Association (ICA) posted reports claiming that chiropractic care can impact the immune system. These claims clash with recommendations from the World Health Organization and World Federation of Chiropractic. We discuss the scientific validity of the claims made in these ICA reports. MAIN BODY: We reviewed the two reports posted by the ICA on their website on March 20 and March 28, 2020. We explored the method used to develop the claim that chiropractic adjustments impact the immune system and discuss the scientific merit of that claim. We provide a response to the ICA reports and explain why this claim lacks scientific credibility and is dangerous to the public. More than 150 researchers from 11 countries reviewed and endorsed our response. CONCLUSION: In their reports, the ICA provided no valid clinical scientific evidence that chiropractic care can impact the immune system. We call on regulatory authorities and professional leaders to take robust political and regulatory action against those claiming that chiropractic adjustments have a clinical impact on the immune system

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

Search for Physics beyond the Standard Model in Events with Overlapping Photons and Jets

Results are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at root s = 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). The spectra of total transverse hadronic energy of candidate events are examined for deviations from the standard model predictions. No statistically significant excess is observed over the expected background. The first cross section limits on new physics processes resulting in such events are set. The results are interpreted as upper limits on the rate of gluino pair production, utilizing a simplified stealth supersymmetry model. The excluded gluino masses extend up to 1.7 TeV, for a neutralino mass of 200 GeV and exceed previous mass constraints set by analyses targeting events with isolated photons.Peer reviewe

Measurement of b jet shapes in proton-proton collisions at root s=5.02 TeV

We present the first study of charged-hadron production associated with jets originating from b quarks in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data sample used in this study was collected with the CMS detector at the CERN LHC and corresponds to an integrated luminosity of 27.4 pb(-1). To characterize the jet substructure, the differential jet shapes, defined as the normalized transverse momentum distribution of charged hadrons as a function of angular distance from the jet axis, are measured for b jets. In addition to the jet shapes, the per-jet yields of charged particles associated with b jets are also quantified, again as a function of the angular distance with respect to the jet axis. Extracted jet shape and particle yield distributions for b jets are compared with results for inclusive jets, as well as with the predictions from the pythia and herwig++ event generators.Peer reviewe