Abstract
A household may learn the importance of stock investment from its siblings. Using the logit and probit models, this paper tests empirically the learning hypothesis that a household is more likely to purchase stocks if its siblings have bought stocks, and finds evidence for the hypothesis. The estimates obtained in the analysis imply that a household’s probability of stock purchases increases by about 1–3 % points if a sibling has purchased stocks. The positive results are not due to alternative explanations, such as uncontrolled correlation of age effects, financial support from siblings, common shocks, or other unobservable correlations. Moreover, the analysis does not support the objection that the positive results may be due to the effects of genes or common parenting.
Similar content being viewed by others
Notes
Evans and Honkapohja (2009) provide a comprehensive review of studies on the learning process in monetary policy.
For example, using data on Swedish twins (from the Swedish Twin Registry) Calvet and Sodini (2014) reported that the adjusted R-squared in estimating the risky share of financial assets is higher for twins communicating more frequently, which suggests that communication between twins may be driving financial decisions. Using the same twin data, Cronqvist et al. (2015b) and Barnea et al. (2010) examined the financial behavior of twins, and the estimated residuals suggested the importance of communication between twins. Other studies that have examined the financial behavior of twins using these data include Cronqvist and Siegel (2015), Cesarini et al. (2010), and Cesarini et al. (2009).
Wachter and Yogo (2010) provided a theoretical framework for this observation.
Related, Bursztyn et al. (2014) studied the impact of social learning in purchases of a financial product designed for a special experiment.
In a related vein, Hong et al. (2005) reported that fund managers tend to purchase stocks that other fund managers in the same city have been buying.
Related, Heimer (2014) reported that social interaction is associated with active portfolio management.
In addition to the data set used for this paper (1999–2013), I could construct an alternative data set containing three survey waves, 1984–1989, 1989–1994, and 1994–1999, because the PSID reported wealth data every 5 years between 1984 and 1999. I use the data set containing data for the period 1999–2013 because it is much larger, comprising seven survey waves with over 10,000 observations. I cannot combine the alternative data set (1984–1999) with the current data set (1999–2013) because of the difference in the periods (5 years in the alternative data set against 2 years in the current data set).
The table reports the 2-year lag because that is the variable used in the empirical analysis.
In the PSID, stocks are defined as non-IRA (individual retirement accounts) stocks, including any shares of stock in publicly held corporations, mutual funds, and investment trusts, but not including any IRAs.
This is the case unless both head and spouse were recorded in the 1968 survey.
For additional details about the data structure, see Tokuoka (2013).
Furthermore, to control for preferences, the analysis below adds dummies indicating the household head’s health conditions, whether the household head is now smoking or has ever smoked, and the number of cigarettes that the household head smokes per day.
The five regions are: northeast, north central, south, west, and others (Alaska and Hawaii). The eight occupation groups are: professional and technical workers; managers (not self-employed); managers (self-employed); clerical and sales workers; craftspersons; operatives and laborers; farmers and farm laborers; and service workers. The 12 industry dummies are: agriculture, forestry, and fishing; mining; construction; manufacturing; transportation, communications, and utilities; wholesale and retail trade; finance, insurance, and real estate; business and repair services; personal services; entertainment and recreation services; professional and related services; and public administration. The occupation and industry groupings are from Carroll and Samwick (1997).
Shive (2010) also investigated the learning impact on stock purchases.
This in fact may be an underestimate of the cumulative impact of siblings’ stock purchases because it measures only the lagged impact. The coefficient on \(DPurSib_{t}\) (third column in Table 2) infers that if a sibling purchases stocks, the probability of household i purchasing stocks increases by 0.1 % points.
Of course, a sibling is more likely to give financial support to the household if it suffers severe financial difficulties (e.g., head’s unemployment). Such a household may not be in a financial position to purchase stocks, even after receiving financial support. That said, below I run regressions to test and deny formally the impact of financial support on stock purchases (one of the possible alternative explanations).
The PSID reports only the total amount of financial support, which includes not only support to a sibling but also other kinds of support (e.g., support for elderly parents).
The results are similar when including the dummy, which takes a value of one when \(DPurSib_{t-2}=1\) and returns from stocks have been in excess of 10 % (not reported here). Using an alternative threshold (e.g., 25 %) gives similarly weak results.
We should not interpret this immediately as providing evidence for learning from parents because as noted in Introduction, the existence of various financial transfers from parents (e.g., inheritances), some of which are perhaps not reported in the survey, requires careful interpretation.
The results are similar when specifying the dummy for parents’ stock purchases, instead of that for parents’ stock market participation.
Barsky et al. (1997) report that (measured) risk tolerance is related to risky behaviors such as smoking.
Cronqvist et al. (2015a) report that the extent of risk taking differs substantially between males and females.
Ameriks and Zeldes (2004) report that the share of stocks in household portfolios declines after the age of 55 years when controlling for other factors.
References
Ameriks J, Zeldes SP (2004) How do household portfolio shares vary with age?. Mimeo, New York
Banerjee A, Fudenberg D (2004) Word-of-mouth learning. Games Econ Behav 46(1):1–22
Barnea A, Cronqvist H, Siegel S (2010) Nature or nurture: what determines investor behavior? J Financ Econ 98(3):583–604
Barsky RB, Kimball MS, Juster FT, Shapiro MD (1997) Preference parameters and behavioral heterogeneity: an experimental approach in the health and retirement survey. Q J Econ 112(2):537–579
Brown JR, Ivkovic Z, Smith PA, Weisbenner S (2008) Neighbors matter: causal community effects and stock market participation. J Finan 63(3):1509–1531
Bursztyn L, Ederer F, Ferman B, Yuchtman N (2014) Understanding mechanisms underlying peer effects: evidence from a field experiment on financial decisions. Econometrica 82(4):1273–1301
Calvet LE, Sodini P (2014) Twin picks: disentangling the determinants of risk-taking in household portfolios. J Finan 69(2):867–906
Campbell JY (2006) Household finance. J Finan 61(4):1553–1604
Cao HH, Han B, Hirshleifer D (2011) Taking the road less traveled by: does conversation eradicate pernicious cascades? J Econ Theory 146(4):1418–1436
Carroll CD (2002) Portfolios of the rich. In: Household portfolios: theory and evidence, MIT Press, Cambridge. http://econ.jhu.edu/people/ccarroll/richportfolios.pdf
Carroll CD, Samwick AA (1997) The nature of precautionary wealth. J Monet Econ 40(1):41–71
Cesarini D, Dawes CT, Johannesson M, Lichtenstein P, Wallace B (2009) Genetic variation in preferences for giving and risk taking. Q J Econ 124(2):809–842
Cesarini D, Johannesson M, Lichtenstein P, Sandewall O, Wallace B (2010) Genetic variation in financial decision-making. J Finan 65(5):1725–1754
Conley TG, Udry CR (2010) Learning about a new technology: pineapple in ghana. Am Econ Rev 100(1):35–69
Cronqvist H, Siegel S (2015) The origins of savings behavior. J Polit Econ 123(1):123–169
Cronqvist H, Previtero A, Siegel S, White RE (2015a) The fetal origins hypothesis in finance: prenatal environment and investor behavior. Mimeo, Ontario
Cronqvist H, Siegel S, Yu F (2015b) Value versus growth investing: why do different investors have different styles? J Finan Econ 117(2):333–349
Dahl GB, Loken KV, Mogstad M (2014) Peer effects in program participation. Am Econ Rev 104(7):2049–2074
Evans GW, Honkapohja S (2009) Expectations, learning and monetary policy: an overview of recent research. Monetary policy under uncertainty and learning 13:027–076
Han B, Hirshleifer D (2013) Self-enhancing transmission bias and active investing. Mimeo, Toronto
Heimer RZ (2014) Friends do let friends buy stocks actively. J Econ Behav Organ 107(Part B):527–540
Hong H, Kubik JD, Stein JC (2004) Social interaction and stock-market participation. J Finan 59(1):137–163
Hong H, Kubik JD, Stein JC (2005) Thy neighbor’s portfolio: word-of-mouth effects in the holdings and trades of money managers. J Finan 60(6):2801–2824
Ivkovic Z, Weisbenner S (2007) Information diffusion effects in individual investors’ common stock purchases: covet thy neighbors’ investment choices. Rev Financ Stud 40(4):1327–1357
Kaustia M, Knupfer S (2008) Do investors overweight personal experience? Evidence from IPO subscriptions. J Finan 63(6):2679–2702
Kaustia M, Knupfer S (2012) Peer performance and stock market entry. J Finan Econ 104(2):321–338
Li G (2014) Information sharing and stock market participation: evidence from extended families. Rev Econ Stat 96(1):151–160
Malmendier U, Nagel S (2011) Depression babies: do macroeconomic experiences affect risk taking? Q J Econ 126(1):373–416
Manski CF (1993) Identification of endogenous social effects: the reflection problem. Rev Econ Stud 60(3):531–542
Manski CF (2000) Economic analysis of social interactions. J Econ Perspect 14(3):115–136
Munshi K (2004) Social learning in a heterogeneous population: technology diffusion in the Indian green revolution. J Dev Econ 73(1):185–213
Shiller RJ (2000) Irrational exuberance. Doubleday, New York City
Shiller RJ, Pound J (1989) Survey evidence on diffusion of interest and information among investors. J Econ Behav Organ 12(1):47–66
Shive S (2010) An epidemic model of investor behavior. J Finan Quant Anal 45(01):169–198
Tokuoka K (2013) Saving response to unemployment of a sibling. J Econ Behav Organ 89(C):58–75
Wachter JA, Yogo M (2010) Why do household portfolio shares rise in wealth? Rev Finan Stud 23(11):3929–3965
Wooldridge JM (2001) Econometric analysis of cross section and panel data, vol 1. The MIT Press, Cambridge
Acknowledgments
I am grateful to Christopher Carroll, Raphael Lam, Yasuhisa Ojima, Rui Ota, and those who participated in the seminars at Johns Hopkins University and Tokyo University on learning in financial decisions for insightful comments. I also thank anonymous referees for helpful comments. This paper is based on the research I started while working at the International Monetary Fund, but the views presented in this paper are those of the author, and should not be attributed to the International Monetary Fund or the Japanese Ministry of Finance.
Author information
Authors and Affiliations
Corresponding author
Appendix: Detailed results of the baseline regression
Appendix: Detailed results of the baseline regression
Table 10 reports the results of Table 2 with a more comprehensive list of control variables. Aside from the key dummies (\(DEntrySib_{t}\), \(DEntrySib_{t-2}\), \(DPurSib_{t}\), and \(DPurSib_{t-2}\)), the lagged stock share in net worth and the dummy variable for white have a significant positive impact on stock purchases (third to fifth columns of Table 10). Education (dummy for head’s college degree) also has a positive impact on stock purchases, although the statistical significance is lower than the stock share and the dummy variable for white.
Rights and permissions
About this article
Cite this article
Tokuoka, K. Is stock investment contagious among siblings?. Empir Econ 52, 1505–1528 (2017). https://doi.org/10.1007/s00181-016-1120-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00181-016-1120-6