This thesis provides a detailed analysis of the so-called `house money' or windfall endowment effect and its main determinants. Chapter 1 provides a detailed survey on the literature related to the house money effect. This effect according to Thaler and Johnson (1990) - refers to the situation where prior gains mitigate the influence of loss aversion and facilitate risk-seeking. The concept borrows its name from the expression employed in the gambling parlance of "playing with the house money", which is used when people gamble while ahead. As the literature has used a variety of concepts and ideas to describe the house money effect, this chapter presents and discusses them within the environment and the related literature that they have emerged. This is done in order to highlight the predominant answers to the main research questions raised in the various strands of the literature, namely: (i) whether people treat money differently depending on its origin; and (ii) the implications of the house money effect for the experimental methodology in economics. The literature is organised and presented according to the context in which the above two research questions have been examined. By presenting results in each particular context, we pin down the contextual differences that might be responsible for the presence (or absence) of the house money effect, and lay the initial ground work to answer a third research question: What drives the house money effect? In this regard, after we demonstrate the context-dependency of the house money effect we present the two main interpretations that it has received, namely that the house money effect is a result of different mental accounting over windfall gains (`windfall effect') or a result of fairness or deservingness concerns ('Lockean desert effect'). Chapter 2 re-examines the house money effect and explores its main driving forces. For that, we employ a novel experimental design utilising a within-subject approach, coupled with the use of three different contexts of economic decisions (a trust game, a set of lotteries and a public good game). Both the within-subject experimental design and the three contexts of economic decisions allow us to better test the two main interpretations of the house money effect. Our experimental data confirm the presence of the house money effect both in the decision to trust (but not in the decision of trustworthiness) in the trust game and in the decision to contribute in the public account of the public good game. However, our findings do not support the hypothesis that changes in risk behaviour of participants are due to different sources of money, suggesting that risk attitudes are robust and independent of the origin of money along the experiment. Therefore, our findings seem to favour interpretations of the house money effect as a result of 'just desert' or fairness preferences rather than the result of different mental accounting over windfall gains. Chapter 3 combines two branches of experimental literature, namely the house money effect and the literature on individual differences in social preferences. Both the house money effect and individual differences have been used extensively to explain cooperation in social dilemmas (and its decline over time). Here, we test the implications of house money on reciprocal behaviour, that is, whether participants in economic experiments are less likely to reciprocate when earned money rather than windfall money is at stake. Using the innovative experimental design of Fischbacher et al. (2001) with strategy method, we classify participants according to their behaviour in a linear public good game, and by adding the within-subject element in our experimental design we test the robustness of this classification across the different origin of endowments. Our results indicate that the types' classification is robust across the origin of money. Contrary to Harrison (2007), we find that participants' decision to free ride or not (contribute or not) is independent of the origin of money, but given that the decision to contribute has been made, contribution levels may vary -actually be lower- when money is earned rather than windfall endowed. We also elicit beliefs about others' contributions and test how these beliefs affected by the "house money" and in turn how they affect the decision to contribute. This discussion relates to what the literature has characterised so far as "anticipatory reciprocity".

We investigate the effect of house money on individual investors. Our empirical evidence suggests that house money effect shows up in real-world financial markets, not just in artificial laboratory experiments. The results reveal a strong house money effect and show that investors tend to buy up trend stocks once they have experienced a prior gain. Only when a significant gain is being considered, does an individual become more inclined to take a risk. When the influence of a significant gain gradually depreciates over time, the greater tendency to take risk also diminishes. We find that individual investors exhibit the disposition effect— reluctant to realize losses and more willing to realize gains. They frequently realize small gains and less frequently take large losses, such a behavior may hurt their wealth because their gains are lower than their losses. Analyses of portfolio holdings reveal that individual investors hold relatively few different stocks and focus on a small number of stocks with which they are familiar. Their investment choice is driven by familiarity bias which diminishes the strength of the house money effect. When evaluate an investment gain, investors’ reference points adapt over time and the currently-salient reference point is the highest stock price attained some time ago.

The dissertation consists of two essays. The first essay investigates the ability of prior returns, relative to some aggregate market returns, to predict future returns on industry style portfolios. By pooling time series of returns across industries for the period between July 1969 and June 2012, we find that prior returns differential predicts one month ahead returns negatively, even in the presence of a set of popular state variables. The predictability remains significant and negative for up to 5 month ahead returns. The predictability is shown to be robust to alternative specifications, estimation methodology and industry classifications. A possible explanation of this finding is based on time–varying (dynamic) loss aversion among investors. More specifically, when combined with house money effects, prior performance has inverse relationship with degree of loss aversion leading to predictability in the next period returns. The second essay examines the nature of time variation in the risk exposure of country mutual funds to the US market movement and to the benchmark foreign market movement. It uses weekly data on 15 closed end funds and 19 exchange traded funds for the sample period between January, 2001 and December, 2012. Conditional factor models are employed to uncover the time variation in the estimated betas through short horizon regressions. The findings of the paper indicate considerable time variation in risk exposure of country mutual funds to the US market and foreign market risk factors. Additional investigation reveals the following observations. First, the US market betas suffer greater variation over the sample period than the target foreign market betas. Second, the overall fluctuation in betas for the closed end funds is found to be higher than that for the exchange traded funds. Third, emerging market funds experience more oscillation in the risk exposure than their developed market counterparts. It is found that a combination of the US macroeconomic state variables and investors’ sentiment can predict future betas significantly. The findings of the paper have important implication for US investors seeking diversification benefits from country mutual funds.

Bakgrund: Coronapandemin präglade under lång tid människors vardag såväl som de finansiella marknaderna. Den kraftiga nedgången i februari - mars år 2020 och den rekordsnabba återhämtningen påverkade privatinvesterare. Dessa investerare stod inför tuffa beslut, och präglades av stress och oro. Under volatila tider sker inte alltid rationella beslut, och denna typ av beslutsmiljö kan påverka investerare att vara mer mottagliga av psykologiska bias. För att undvika att gå i samma fällor, är det av intresse att kartlägga börspsykologiska faktorers påverkan på privatinvesterares agerande och vilken effekt det har på deras diversifiering i aktieportföljen. Eventuella skillnader i agerande under börsnedgångarna visar även om investerarna själva lärde sig någonting från den första börsnedgången och ändrade sitt beteende till den andra börsnedgången. Syfte: Syftet med studien är att kartlägga privatinvesterares agerande på aktiemarknaden under Coronapandemin. Detta för att kunna uttala sig om, privatinvesterares beteende under börsnedgången i februari - mars 2020, samt den andra börsnedgången i oktober samma år. Genom att undersöka två tidsperioder går det att observera skillnader i beteende. Metod: Studien använde sig av en enkätstudie med tvärsnittsdesign för att på generell nivå ha möjlighet till att uttala sig om privatinvesterares agerande under börsnedgångarna. Slutsats: Studien har visat att samtliga undersökta börspsykologiska bias har påverkat privatinvesterare under båda börsnedgångarna men det finns dock skillnader mellan perioderna. Om respondenterna själva får beskriva deras agerande har många angett att de har agerat rationellt under krisen, något som tidigare forskning också konstaterat. Diversifieringen har ökat i aktieportföljen efter börsnedgångarna, jämfört med hur det såg ut vid slutet av 2019. Det är dock inte säkerställt att detta är en effekt av nedgångarna. Slutligen finns det även skillnader i börspsykologiska faktorer och diversifiering mellan demografiska faktorer och erfarenhet från tidigare kriser. / Background: The Corona pandemic has affected people’s everyday life as well as the financial markets. The big decline in the stock market that happened in February-March 2020 and the record fast recovery impacted private investors in a big way. Investors had difficult decisions to make during times of stress and worry, which does not always lead to optimal decisions. The investors could be more affected by biases during times of crisis. To avoid walking into the same traps again it is of investor’s interest to map psychological biases and how they affect the diversification in their stock portfolios. Eventual differences in behavior between the stock market decline in February-Mars and the one in October could be spotted by comparing the two periods. This would show if the respondents themselves learned from the first stock market decline to the second one, hence changing their behavior. Purpose: The purpose of this study is to map private investors’ behavior in the stock market during the Corona pandemic. This will make it possible to discuss private investors’ behavior during the stock market declines in February-March 2020 as well as the one in October the same year. This will make it possible to see differences in behavior. Method: The study used a survey study with cross-sectional design to be able to discuss private investors’ behavior at a general level. Conclusion: The study has shown that all studied psychological biases to affect private investors during the stock market declines, showing there are differences between these periods. If the respondents describe their own actions, then many of say themselves that they acted rational during the crisis, something that previous studies have shown. The diversification has also increased after the stock market declines compared to how it was at the end of 2019, but it is not certain that it is an effect of the stock market declines. There are also differences between demographic factors and experience from previous crises with regards to psychological biases and diversification.

Abstract This dissertation contributes to the research on behavioral biases among individual investors by demonstrating how investors increase their portfolio volatility, i.e., risk, following favorable outcomes. This work also shows the influence of the first investment on subsequent risk-taking preferences. It also shows how stock prices, through unrealized capital gains, create an evident momentum effect following both bull and bear markets. The work is quite new because house money, quasi-hedonic editing rules and mental accounting are not frequently used in the financial literature. The data used are from the Finnish Central Securities Depository (FCSD), which is unique in the financial research literature. The results of the first essay indicate that individual investors purchase stocks that increase portfolio risk or volatility after a period of negative market returns. These results propose that investors attribute these returns to themselves. Therefore, they are supporting a self-attribution bias. Ergo, investors gamble with their winnings over the next investment session. This behavior is consistent with the house money effect, which has not been before analyzed in the background of the stock market. Inexperienced investors are particularly prone to this effect. The second essay investigates the effect of the outcome of the first investment on subsequent risk-taking preferences, which has not been previously analyzed in the context of financial markets. The database allows for analyses of new investors making their first stock market investment. The results show that in first or subsequent investments the win effect is stronger. The effect in the first investment situation results in higher volatility. Therefore, the result suggests that realized money is more likely to be risked in the situation of the first stock than in the situation of the other stocks. The third essay, using a technique not before applied to research regarding momentum asymmetry, shows that deviations from the holdings- or volume-based reference price, i.e., the so-called capital gains overhang, can account for momentum. The results propose that after accounting for the disposition effect, overconfidence and biased self-attribution are not able to explain momentum asymmetry. / Tiivistelmä Väitöskirja edistää yksittäisten sijoittajien käyttäytymishäiriöitä koskevaa tutkimusta osoittamalla, kuinka sijoittajat lisäävät salkun riskiä myönteisten tulosten jälkeen. Väitöskirja osoittaa myös, kuinka sijoittajat lisäävät salkun riskisyyttä ensimmäistä investointia myöhemmille riskinottopäätöksille. Se esittää myös, kuinka realisoitumattomat myyntivoitot aiheuttavat ilmeisen momentum-vaikutuksen, sekä nousevilla että laskevilla markkinoilla. Teos on melko uusi, koska talon rahoilla pelaamista, lähes-hedonisia muokkaussääntöjä ja henkistä kirjanpitoa ei käytetä kovin paljon talouskirjallisuudessa. Käytetyt tiedot ovat Rahoitustutkimuksen ainutlaatuinen Suomen Arvopaperikeskus (FCSD) aineisto. Ensimmäisessä esseessä, kun sijoittajat ovat saavuttaneet tuottoja negatiivisten markkinatuottojen jälkeen, he ostavat osakkeita, jotka lisäävät salkun riskisyyttä. Nämä tulokset viittaavat siihen, että sijoittajat määrittävät nämä tuotot itselleen. Siksi he tukevat itsemääräämisoikeutta, joten sijoittajat pelaavat voitoillaan seuraavan sijoituskauden aikana. Käyttäytyminen on yhdenmukainen talon rahan vaikutuksen kanssa. Vaikutus, jota ei ole aiemmin analysoitu osakemarkkinoiden yhteydessä. Kokemattomat sijoittajat ovat erityisen alttiita tästä vaikutuksesta. Toinen essee tutkii ensimmäisen investoinnin tuloksen vaikutusta myöhempään riskinottopäätökseen. Sitä ei ole aiemmin analysoitu rahoitusmarkkinoiden yhteydessä. Tietokannan avulla analysoidaan uusia sijoittajia, jotka tekevät ensimmäisen pörssi-investoinninsa. Tulokset osoittavat, että kummassakin tapauksessa, ensimmäiset tai toiset voitot, voittoefektit ovat voimakkaammat kuin voitto-dummy ja ensimmäisellä tasolla olevat voitot antavat suuremman vaikutuksen riskisyyteen. Kiinnostavaa on se, että tulo, joka kertoo, onko realisoitunut raha todennäköisemmin riski ensimmäisessä osakkeessa, on suurempi kuin riski muissa osakkeissa. Kolmas essee käyttää menetelmää, jota ei ole aikaisemmin käytetty momentum-symmetrian tutkimukseen. Tämä tutkimus osoittaa, että poikkeamat volyymi- tai omistukseen perustuvasta viitehinnasta, eli ns. myyntivoiton ylitys, voivat selittää momentumia. Tulokset viittaavat siihen, että disposition ja liiallisen itseluottamuksen ja harhaisen itse-attribuution jälkeen ei voida suurella todennäköisyydellä selittää momentumin epäsymmetriaa.