Debunking the Monday Irrationality through the External Affection of Investors

Rayenda Brahmana(1*), Chee-Wooi Hooy(2), Zamri Ahmad(3)

(1) Faculty of Economics and Business Universiti Malaysia Sarawak
(2) School of Management Universiti Sains Malaysia
(3) School of Management Universiti Sains Malaysia
(*) Corresponding Author


This study aims to reveal the mechanism of the influences of the full moon and high temperatures on investors’ Monday irrationality. In contrast to other studies, this research was built under a retroductive approach by using a time series quasi experimental study. Investors were directly assessed for their irrationality by using an adapted psychometric test on 4 occasions. The results indicate that there were indeed effects of the full moon and high temperatures on investors’ irrationality. Because the full moon and high temperatures frequently occurred on Mondays, it is most probably those two variables that were the drivers of the Monday irrationality. In the end, we concluded that the rational behaviour assumption can no longer be held. Instead of rationality, the investors were quasi rational. The utility function of Von Neumann-Morgenstern in decision making has to be replaced by the hedonic utility.

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Abraham, A., and D. L. Ikenberry. 1994. The individual investor and the weekend effect. The Journal of Financial and Quantitative Analysis 29 (2): 263-277.

Angel, J. J., S.E. Christophe, and M. G. Ferri. 2003. A close look at short selling on Nasdaq. Financial Analysts Journal 59 (6): 66-74.

Allison, C. W., and J. Hayes. 1996. The cognitive style index: A measure of intuition-analysis for organizational research. Journal of Management Studies 33 (1): 119-135.

Barclay D. W., R. Thompson, and C. Higgins. 1995. The Partial Least Squares (PLS) approach to causal modeling: Personal computer adoption and use an illustration. Technology Studies 2 (2): 285–309.

Barr, W. 2000. Lunar revisited: The influence of the moon on mental health and quality of life. Journal Psychosocial Nurse Mental Health Serice 38 (5): 28-35

Basu, R., and J. M. Samet. 2002. Relation between elevated ambient temperature and mortality: A review of the epidemiologic evidence. Epidemiologic Reviews 24: 190-202.

Bell, D., and E. Levin. 1998. What causes intra-week regularities in stock returns? Some evidence from the UK. Applied financial economics 8 (4): 353-357.

Berument, H., and H. Kiymaz. 2001. The day of the week effect on stock market volatility. Journal of Economics and Finance 25 (2): 181-193.

Brahmana, R., C. W. Hooy, and Z. Ahmad. 2012a. Psychological factors on irrational financial decision making: The case of day-of-the week anomaly. Humanomics 28 (4): 236-257.

Brahmana, R., C. W. Hooy, and Z. Ahmad. 2012b. Weather, investor irrationality and day-of-the-week anomaly: case of Indonesia. Journal of Bioeconomics 14 (2): 129-146.

Brahmana, R., C. W. Hooy, and Z. Ahmad. 2014a. The role of weather on investors’ monday irrationality: Insights from Malaysia. Contemporary Economics 8 (2): 175-190.

Brahmana, R., C. W. Hooy, and Z. Ahmad. 2014b. Moon phase effect on investor psychology and stock trading performance. International Journal of Social Economics 41 (3): 182-200.

Brahmana, R., C. W. Hooy, and Z. Ahmad. 2014c. Moon Phase as the cause of Monday irrationality: Case of Asean day of the week anomaly. The International Journal of Economic Behavior-IJEB 4 (1): 51-65.

Brahmana, R., C. W. Hooy, and Z. Ahmad. 2015. Does tropical weather condition affect investor behaviour? Case of the Indonesian stock market. Global Business and Economics Review 17 (2): 188-202.

Buss, A. H., and M. P. Perry. 1992. The aggression questionnaire. Journal of Personality and Social Psychology 63: 452-459.

Butler, D., and G. Loomes. 2002. Quasi rational search under incomplete information: Some evidence from experiments. Manchester School 65 (2): 127-144

Card, D., and B. P. McCall. 1996. Is workers’ compensation covering uninsured medical cost? Evidence from the Monday effect. Industrial and Labour Relation Review 49 (4): 690-706.

Cella, D. F., P. B. Jacobsen, E. J. Orav, J. C. Holland, P. M. Silberfarb, and S. Rafla. 1987. A brief POMS measure of distress for cancer patients. Journal of Chronic Diseases 40 (10): 939-942.

Chen, H., and V. Singal. 2003. Role of speculative short sales in price formation: The case of the weekend effect. The Journal of Finance 58 (2): 685-706.

Chugh, D., and M. X. Bazerman. 2007. Bounded awareness: What you fail to see can hurt you. Mind and Society 6: 1-18

Clare, A. D., Z. Psaradakis, and S. H. Thomas. 1995. An analysis of seasonality in the U.K. equity market. The Economic Journal 105 (429): p. 398-409.

Compeau D. R., C. A. Higgins, S. Huff. 1999. Social cognitive theory and individual reactions to computing technology: A longitudinal-study. MIS Quaterly 23 (2):145–158.

Cunningham, M. R. 1979. Weather, mood and helping behaviour: Quasi-experiment with the sunshine samaritan. Journal of Personality and Social Psychology 37: 1947–1956.

Daniel, K., D. Hirshleifer, and A. Subrahmanyam. 1998. Investor psychology and security market under and over reaction. Journal of Finance 53 (6): 1839-1885.

Dewey, E. R. 1971. Cycles: The Mysterious Forces that Trigger Events. Foundation for the Study of Cycles, New York

Dichev, I. D., and T. D. Janes. 2003. Lunar cycle effects in stock returns. Journal of Private Equity 6 (Fall): 8 –29.

Dobbins, J. G. 1982. A menstrual anomaly: Calendar cycling in a Malays population. Medical Journal of Malaysia 37 (3): 253-256.

Forgas, J. P. 1989. Moods effect on decision making strategies. Australia Journal of Psychology 41: 197-214.

Forgas, J. P. 1994. The role of emotion in social judgement: An introductory review and an affect infusion model. European Journal of Social Psychology 24: 1-24.

Forgas, J. P. 1995. Mood and judgment: The affect intrusion model. Psychology Bulletin 117: 39-66.

Fornell C., and D. F. Larcker. 1981. Evaluating structural equation models with unobservable variables and measurement error. Journal of Marketing Research 18 (1): 39-50.

Forster, P. M. D. F., and S. Solomon. 2003. Observations of a “weekend effect” in diurnal temperature range. Proceedings of the National Academy of Sciences 100 (20): 11225-11230.

French, K. R. 1980. Stock returns and the weekend effect. Journal of Financial Economics 8: 55-69.

Gao, Q. 2009. Lunar Phases Effect in Chinese Stock Returns. International Conference on Business Intelligence and Financial Engineering. Beijing, China July 24-July 26

Gill, C. H. and P. L. Scharer. 1996. Why do they get it on Friday but misspell it on Monday? Language Arts 73 (2): 89-96

Goh, S. K., and K. N. Wong. 2011. Malaysia’s outward FDI: The effects of market size and government policy. Journal of Policy Modelling 33:497–510.

Hair J. F., W. C. Black, B. J. Babin, and R. E. Anderson. 2010. Multivariate Data Analysis. Upper Saddle River: Prentice-Hall.

Hansen, A., P. Bi, M. Nitschke, P. Ryan. D. Pisaniello, and G. Tucker. 2008. The effect of heat waves on mental health in a temperate Australian city. Environmental Health Perspective 116 (10): 1369-1375.

Herbst, A. 2007. Lunacy in the stock market—What is the evidence? Journal of Bioeconomics 9: 1-18.

Hirshleifer, D., and T. Shumway. 2003. Good day sunshine: Stock returns and the weather. The Journal of Finance 58 (3): 1009-1032.

Hockey, G. R. J., A. John Maule, P. J. Clough, and L. Bdzola. 2000. Effects of negative mood states on risk in everyday decision making. Cognition and Emotion 14 (6): 823-855.

Howarth, E., and M. S. Hoffman. 1984. A multidimensional approach to the relationship between mood and weather. British Journal of Psychology 75 (1): 15-23.

Isen, A. M., and N. Geva. 1987. The influence of positive effects on acceptable levels of risk: The person with a large canoe has a large worry. Organization Behaviour and Human Decision Process 39: 145-154

Isen, A. M., T. E. Shalker, M. Clark, and L. Karp. 1978. Affect, accessibility of material in memory and behavior: A cognitive loop? Journal of Personality and Social Psychology 36: 1-12.

Janis, I. L., and L. Mann. 1977. Decision Making: A Psychological Analysis of Conflict, Choice, and Commitment. New York: Free Press

Kahneman, D., and A. Tversky. 1979. Prospect theory: An analysis of decision under risk. Econometrica 47: 263-292.

Kahneman, D., E. Diener, and N. Schwartz. 1999. Well Being: The Foundation of Hedonic Psychology. New York: Russel Sage Foundation

Kamstra, M. J., A. K. Lisa, and D. L. Maurice. 2000. Winter blues: Seasonal affective disorder (SAD): The January effect, and stock market returns. Working Paper.

Kane, F. J., R. J. Daly, J. A. Ewing, and M. H. Keeler. 1967. Mood and behavioural changes with progestational agents. The British Journal of Psychiatry 113 (496): 265-268.

Koeske, G. F., S. A. Kirk, R. D. Koeske, and M. B. Rauktis. 1994. Measuring the Monday blues: Validation of the job satisfaction scale for the human services. Social Work Research 18 (1): 27-35

Kovats, R. S., and L. K. Ebie. 2006. Heatwaves and public health in Europe. The European Journal of Public Health 16 (6): 592-599.

Krämer, W., and R. Runde. 1997. Stocks and the weather: An exercise in data mining or yet another capital market anomaly? Empirical Economics 22: 637-641.

Krebs, D., and R. Blackman. 1999. Psychology: A First Encounter. New Jersey: Harcourt College Pub.

Lai, M. M., K. L. T. Low, and M-L. Lai. 2010. Are Malaysian investors rational? Journal of Psychology and Financial Market 2 (4): 210-215

.Lieber, A. L., 1978. The Lunar Effect. Garden City, NY: Doubleday

Lim, S. Y., and R. C. J. Chia. 2010. Stock market calendar anomalies: Evidence from ASEAN-5 stock markets. Economics Bulletin 30: 996-1005.

Lim, S. Y., C. M. Ho, and B. E. Dollery. 2010. An empirical analysis of calendar anomalies in the Malaysian stock market. Applied Financial Economics 20: 255-264.

Lucey, B. M., and M. Dowling. 2005. The role of feelings in decision making. Journal of Economics Survey 19 (2): 211-231.

McNair, D., M. Lorr, and L. Droppleman. 1989. Profile of Mood States.

Muhammad. N. M. N., and N. Ismail. 2008. Investment decision behaviour: Are investors rational or irrational. Proceeding of East Coast Economic Region Development Conference (15-17 December 2008), Kota Bharu, Kelantan.

Muvakami, S., K. Otsuka, Y. Kubo, M. Shinagawa, T. Yamanaka, S. Ohkawa, and Y. Kitaura. 2004. Repeated ambulatory monitoring reveals a Monday morning surge in blood pressure in a communally-dwelling population. American Journal of Hypertension 17: 1179-1183

Nelson, R. G., and D. A. Bessler. 2006. Quasi rational: Experimental evidence. Journal of Forecasting 11 (2): 141-156.

Nunnally J., and I. Berstein. 1994. Psychometric Theory. New York: McGraw-Hill.

Pardo, A., and E. Valor. 2003. Spanish stock returns: Where is the weather effect? European Financial Management 9 (1): 117-126.

Saunders, Jr, E. M. 1993. Stock prices and Wall Street weather. The American Economic Review 83 (5) (Dec): 1337-1345.

Schwarz, N., and G. L. Clore. 1983. Mood, misattribution, and judgment of well-being: Informative and directive function of affective States. Journal of Personality and Social Psychology 45 (3): 513-523.

Sekaran, U., and R. Bougie. 2010. Research methods for business: A skill building approach. Wiley, UK.

Shefrin, H. and M. Statman. 1985. The disposition to sell winners too early and ride losers too long: Theory and evidence. The Journal of Finance 40 (3): 777-790.

Slovic, P. 1999. Perceived risk, trust, and democracy. In G. Cvetkovich and R. E. Lofstedt (Eds). Social Trust and Management of Risk (pp.42-52). London: Earthscan

Slovic, P., M. L. Finucane, E. Peters, and D. MacGregor. 2004. Risk as analysis and risk as feelings: some thoughts about affect, reason, risk, and rationality. Risk Analysis 24: 311-322.

Thaler, R. 1994. Quasi Rational Economics. Russel Sage Foundation.

Trombley, M. A. 1997. Stock prices and Wall Street weather: Additional evidence. Quarterly Journal of Business and Economics 36: 11–21.

Tvede, L. 2002. The Psychology of Finance (Revised ed.). John Wiley and Son.

Tversky, A., and D. Kahneman. 1992. Advances in prospect theory: Cumulative representation of uncertainty. Journal of Risk and uncertainty 5 (4): 297-323.

Viale, R. 2008. Cognitive constraints of economic rationality. In Simon, H. A., M. Egidi, R. Viale, and R. L. Marris (Eds.), Economics, Bounded Rationality, and the Cognitive Revolution (pp. 174-181). Cheltenham: Edward Elgar Publishing

Warneryd, K. E. 2001. Stock Market Psychology: How People Value and Trade Stock. Edward Elgar Publishing.

Wilkinson, G. 1997. Lunar cycle and consultation for anxiety and depression in general practice. International Journal of Social Psychiatry 43 (1): 29-34.

Willich, S. N., H. Lowel, M. Lewis, A. Hormann, H. R. Arntz, and U. Keil. 1994. Weekly variation of acute myocardial infarction, increased Monday risk in the working population. Journal of America Heart Association, 90, 87-93

Wong, K. A., T. H. Hui, and C. Y. Chan. 1992. Day of the week effects: Evidence from developing stock markets. Applied Financial Economics 2 (1): 49-56.

Wong, W-C., and M-M. Lai. 2009. Investor behaviour and decision making style: A Malaysian perspective. Bankers Journal Malaysia 133: 3-13.

Yuan, K., L. Zheng, and Q. Zhu. 2006. Are investor moonstruck? Lunar phases and stock returns. Journal of Empirical Finance 1 (3): 1-23.


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