scholarly journals Cognitive Biases on the Iran Stock Exchange: Unsupervised Learning Approach to Examining Feature Bundles in Investors’ Portfolios

2021 ◽  
Vol 11 (22) ◽  
pp. 10916
Author(s):  
Adele Ossareh ◽  
Mohammad Saeed Pourjafar ◽  
Tomasz Kopczewski

This paper innovatively analyses the joint occurrence of cognitive biases in groups of stock exchange investors. It considers jointly a number of common fallacies: confirmation bias, loss aversion, gambler’s fallacy, availability cascade, hot-hand fallacy, bandwagon effect, and Dunning–Kruger effect, which have hitherto been studied separately. The paper aims to highlight the diverse range of investor’s profiles which are characterised by such fallacies, and the considerable differences observed based on their age, stock market experience and perception of market trends. The analysis is based on k-means and hierarchical clustering, feature importance and Principal Component Analysis, which were applied to data from the Tehran Stock Exchange. There are a few essential findings which contribute to the existing literature. Firstly, the results show that gender does not have a role to play in diversifying the investors’ profiles. Secondly, cognitive biases are bundled, and we distinguish four investors’ profiles; thus, they should be analysed jointly, not separately. Thirdly, the exposure to cognitive biases differs significantly due to the individual features of investors. The group most vulnerable to almost all analysed biases are inexperienced investors, who are pessimistic about market developments and have invested a large amount. Fourthly, the ages of investors are essential only in connection with other factors such as experience, market perception and investment exposure. Young (20–40 years), experienced investors with huge investments (+1000 mln rials/+24,000 USD) are mostly less exposed to all biases and much less risk-averse. Additionally, older (50+) and experienced investors (5–10 years) who are more optimistic about trends (hot hand bias) were affected much less by cognitive biases, only showing vulnerability to the Dunning–Kruger effect. Fifthly, more than 40% of investors apply consultation and technical analysis approaches to succeed in trading. Finally, from a methodological perspective, this study shows that unsupervised learning methods are effective in profiling investors and bundling similar behaviours.

1998 ◽  
Vol 4 (1) ◽  
pp. 49 ◽  
Author(s):  
Lucio Naccarella

A descriptive analysis of community-based health promotion projects conducted by Divisions of General Practice between 1993 and 1994 and in 1996 is provided, and their design, evaluation, impact and appropriateness are considered. A total of 55 community-based health promotion projects were funded between 1993 and 1994. Analysis of the 1993 and 1994 projects revealed that: most project goals and objectives lacked clarity and measurability; almost all projects undertook some form of needs assessment; projects tended not to be targeted; participation rates and reporting varied greatly; and project evaluations were designed to measure process and impact at the individual level, rather than on a system wide level. Fifty comparable community-based health promotion projects were funded in 1996.An analysis of project proposals revealed that they were designed on the whole to be more targeted, intersectoral, collaborative and to use multiple settings and strategies than their 1993 and 1994 counterparts. Projects have increased the visibility and capacity of general practitioners (GPs) to engage in community-based health promotion, and provide evidence that they can do more than individual service provision activities, such as community-based health promotion in a diverse range of settings, and with a broad range of population groups.


Author(s):  
Hyeuk Kim

Unsupervised learning in machine learning divides data into several groups. The observations in the same group have similar characteristics and the observations in the different groups have the different characteristics. In the paper, we classify data by partitioning around medoids which have some advantages over the k-means clustering. We apply it to baseball players in Korea Baseball League. We also apply the principal component analysis to data and draw the graph using two components for axis. We interpret the meaning of the clustering graphically through the procedure. The combination of the partitioning around medoids and the principal component analysis can be used to any other data and the approach makes us to figure out the characteristics easily.


2020 ◽  
Vol 15 ◽  
Author(s):  
Shuwen Zhang ◽  
Qiang Su ◽  
Qin Chen

Abstract: Major animal diseases pose a great threat to animal husbandry and human beings. With the deepening of globalization and the abundance of data resources, the prediction and analysis of animal diseases by using big data are becoming more and more important. The focus of machine learning is to make computers learn how to learn from data and use the learned experience to analyze and predict. Firstly, this paper introduces the animal epidemic situation and machine learning. Then it briefly introduces the application of machine learning in animal disease analysis and prediction. Machine learning is mainly divided into supervised learning and unsupervised learning. Supervised learning includes support vector machines, naive bayes, decision trees, random forests, logistic regression, artificial neural networks, deep learning, and AdaBoost. Unsupervised learning has maximum expectation algorithm, principal component analysis hierarchical clustering algorithm and maxent. Through the discussion of this paper, people have a clearer concept of machine learning and understand its application prospect in animal diseases.


2019 ◽  
Vol 130 (629) ◽  
pp. 1384-1415 ◽  
Author(s):  
Ralph Hertwig ◽  
Michael D Ryall

ABSTRACT Thaler and Sunstein (2008) advance the concept of ‘nudge’ policies—non-regulatory and non-fiscal mechanisms designed to enlist people's cognitive biases or motivational deficits so as to guide their behaviour in a desired direction. A core assumption of this approach is that policymakers make artful use of people's cognitive biases and motivational deficits in ways that serve the ultimate interests of the nudged individual. We analyse a model of dynamic policymaking in which the policymaker's preferences are not always aligned with those of the individual. One novelty of our set-up is that the policymaker has the option to implement a ‘boost’ policy, equipping the individual with the competence to overcome the nudge-enabling bias once and for all. Our main result identifies conditions under which the policymaker chooses not to boost in order to preserve the option of using the nudge (and its associated bias) in the future—even though boosting is in the immediate best interests of both the policymaker and the individual. We extend our analysis to situations in which the policymaker can be removed (e.g., through an election) and in which the policymaker is similarly prone to bias. We conclude with a discussion of some policy implications of these findings.


2009 ◽  
Vol 1 (1) ◽  
Author(s):  
Ranjit SINGH ◽  
Amalesh BHOWAL ◽  
Varun BAWARI

Purpose – The purpose of this paper is to investigate the change in the level of the wealth of the shareholders’ before the demerger and after the demerger.Design/methodology/approach – In the present study the data relating to share prices has been taken from the official website of Bombay Stock Exchange. Here the average of the six months price of the demerged company before demerger and average six months price or the average price upto 31st of July, 2007 has been collected of demerged and resultant company after demerger. Findings – It is found that after demerger there is increase in the total wealth of the shareholders in almost all the cases.Research limitations/implications – Given the nature of this study, generalizations cannot be made as the study is conducted in a bullish market. The time specific character of the subject matter is an opportunity for future longitudinal research.Practical implications – Presently de-mergers are creating enormous wealth for shareholders. It is because of the negative synergy. Due to the demerger this negative synergy is removed and the value is unlocked. However, Investors should differentiate between genuine attempts at value creation and de-mergers undertaken to create hype around the stocks. Stay away from dubious companies that want to manipulate prices. Investors should focus on the quality of management and corporate governance record of the companyOriginality/value – The study is the first of its kind and hence original in nature.Article Type: Research paperKeyword(s): Demerger, Demerged Company, Resultant Company, Negative Synergy, Shareholders Wealth.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1187
Author(s):  
Ivana Generalić Mekinić ◽  
Vida Šimat ◽  
Viktorija Botić ◽  
Anita Crnjac ◽  
Marina Smoljo ◽  
...  

In this study, the influences of temperature (20, 40 and 60 °C) and extraction solvents (water, ethanol) on the ultrasound-assisted extraction of phenolics from the Adriatic macroalgae Dictyota dichotoma and Padina pavonica were studied. The extracts were analysed for major phenolic sub-groups (total phenolics, flavonoids and tannins) using spectrometric methods, while the individual phenolics were detected by HPLC. The antioxidant activities were evaluated using three methods: Ferric Reducing/Antioxidant Power (FRAP), scavenging of the stabile 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and Oxygen Radical Antioxidant Capacity (ORAC). The aim of the study was also to find the connection between the chemical composition of the extracts and their biological activity. Therefore, principal component analysis (PCA), which permits simple representation of different sample data and better visualisation of their correlations, was used. Higher extraction yields of the total phenolics, flavonoids and tannins were obtained using an alcoholic solvent, while a general conclusion about the applied temperature was not established. These extracts also showed good antioxidant activity, especially D. dichotoma extracts, with high reducing capacity (690–792 mM TE) and ORAC values (38.7–40.8 mM TE in 400-fold diluted extracts). The PCA pointed out the significant influence of flavonoids and tannins on the investigated properties. The results of this investigation could be interesting for future studies dealing with the application of these two algae in foods, cosmetics and pharmaceuticals.


2009 ◽  
Vol 57 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Clifford K. Madsen ◽  
John M. Geringer ◽  
Katia Madsen

Attention to subtle changes in music, whether inadvertent or purposeful, occupies a great deal of practice and rehearsal time for the performer. Regardless of the extremely subtle acoustic changes that have been found to be perceptible within almost all studies, it is the total overall effect that most occupies the individual listener. This study investigated perception of digitally edited performances of Johann Strauss's Blue Danube Waltz, all performed by the Vienna Philharmonic Orchestra with various conductors across an 18-year period. Two groups of string musicians in grades 7 through 12 participated ( N = 104). One group was an intact class; the second was a group of summer camp students. All participants listened to two conditions: (a) audio only and (b) audio-video combination. Results indicated that there were no significant differences between groups and that no one was able to identify correctly that there were five different conductors in the audio-only condition. Results were much the same as earlier research with college students. In addition, many students indicated that there were differences in the audio portions of the two conditions when in fact there were not.


1975 ◽  
Vol 69 (2) ◽  
pp. 607-614 ◽  
Author(s):  
Vernon Van Dyke

In A Theory of Justice, John Rawls assumes that the principles of justice are for individuals in a society, and in general he assumes that the society is an ethnically homogeneous state. He thus follows the tradition associated with the dominant form of the social contract theory, which focuses on the individual and the state. His assumptions neglect the fact that almost all states are ethnically plural or heterogeneous, and that many of them confer special status and rights on ethnic groups as collective entities; for example, many of them confer special status and rights on indigenous groups, on groups disadvantaged by prior discrimination, and on minorities and other groups conceded a right to survive as distinct cultural entities. Status and rights for groups necessarily mean differentiation among individuals depending on their membership; and this in turn means that a theory of justice that focuses on the individual and neglects the group both fails to account for existing practices and fails to give guidance where the practices are at issue.


2018 ◽  
Vol 10 (11) ◽  
pp. 4112 ◽  
Author(s):  
Alessandra Durazzo ◽  
Johannes Kiefer ◽  
Massimo Lucarini ◽  
Emanuela Camilli ◽  
Stefania Marconi ◽  
...  

Italian cuisine and its traditional recipes experience an ever-increasing popularity around the world. The “Integrated Approach” is the key to modern food research and the innovative challenge for analyzing and modeling agro-food systems in their totality. The present study aims at applying and evaluating Fourier Transformed Infrared (FTIR) spectroscopy for the analysis of complex food matrices and food preparations. Nine traditional Italian recipes, including First courses, One-dish meals, Side courses, and Desserts, were selected and experimentally prepared. Prior to their analysis via FTIR spectroscopy, the samples were homogenized and lyophilized. The IR spectroscopic characterization and the assignment of the main bands was carried out. Numerous peaks, which correspond to functional groups and modes of vibration of the individual components, were highlighted. The spectra are affected by both the preparation procedures, the cooking methods, and the cooking time. The qualitative analysis of the major functional groups can serve as a basis for a discrimination of the products and the investigation of fraud. For this purpose, the FTIR spectra were evaluated using Principal Component Analysis (PCA). Our results show how the utilization of vibrational spectroscopy combined with a well-established chemometric data analysis method represents a potentially powerful tool in research linked to the food sector and beyond. This study is a first step towards the development of new indicators of food quality.


2013 ◽  
Vol 37 (4) ◽  
pp. 617-624 ◽  
Author(s):  
MJ Hasan ◽  
Umma Kulsum ◽  
MMH Rahman ◽  
MMH Chowdhury ◽  
AZMKA Chowdhury

Genetic divergence of 40 parental lines comprising 30 restorer and 10 maintainer lines were studied through Mohalanobis's D2 and principal component analysis for eleven characters. Genotypes were grouped into five different clusters. Cluster V comprised maximum number of genotypes (thirteen) followed by cluster I and II. The inter-cluster distance was maximum between clusters I and V (13.495) indicating wide genetic diversity between these two clusters followed by the distance between cluster I and 11 (9.489), cluster IV, and cluster V (8.969) and cluster I and cluster III (8.039). The minimum inter-cluster distance was observed between cluster II and cluster III (3.034) followed by cluster 111 and cluster IV (3.834) and cluster II and cluster V (4.945) indicating that the genotypes of these clusters were genetically close. The intra cluster distance in the entire five clusters was more or less low which indicated that the genotypes within the same cluster were closely related. Among the characters panicle weight contributed most for divergence in the studied parental lines. Difference in cluster means existed for almost all the characters studied. Highest mean value for number of effective tillers (7.8), days to 50% flowering (95.5), panicles/m2 (192.6), panicle weight (2.9), spikelet fertility (84.8), number of grains/panicle (177.8), days to maturity (123.6), and grain yield/plot (1065.5) were observed in cluster I indicated the parental lines fallen in this cluster having the genetic potentiality to contribute better for yield maximization of hybrid rice. DOI: http://dx.doi.org/10.3329/bjar.v37i4.14386 Bangladesh J. Agril. Res. 37(4): 617-624, December 2012


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