This thesis analyzes the optimal strategies of rational agents in incomplete financial markets. The incompleteness may arise from the stochastic volatility of stock prices, in which case we study the optimal pricing and hedging strategies of an option trader. We introduce a new concept that we call the relative indifference price, which is the price at which a trader is indifferent to trade in an additional option, given that he is currently holding and dynamically hedging a portfolio of options. We find that the appropriate volatility risk premium depends on the trader's risk aversion coeffcient and his portfolio position before selling or buying the additional option. More generally, the incompleteness of the market may arise from both the drift and volatility of the stock being driven by a correlated factor. In this setting, we study the optimal consumption and investment policies of CARA, conservative CRRA and aggressive CRRA agents. In particular, we provide interpretations of the non-myopic investment in terms of martingale measures and the risk monitoring strategy of a path-dependent option. / text

Sammanfattning Den finansiella marknaden har under de senaste decennierna till stor del präglats av både stark ekonomisk tillväxt och stora kriser, detta har lett till att risken relaterad till sparande och investeringar har blivit allt viktigare att kontrollera och undersöka. Samtidigt visar statistik från SCB att de svenska hushållen investerar allt mindre i aktier vilket kan skapa problem, både för den finansiella branschen i sig och det framtida välståndet. Dagens pensionssystem riskerar att inte klara framtidens ökande utbetalningsnivåer som krävs för att underhålla en allt större, äldre befolkning, som även lever allt längre. Detta är ett problem som gäller för hela EU och därför blir det allt viktigare med ett privat sparande, och därigenom att investera rätt. För att hjälpa privatpersoner att investera rätt, genom att utnyttja sin nivå av risktolerans, samtidigt som man gör det lättare för kreditgivare och rådgivare att kunna erbjuda korrekta produkter och investeringsstrategier, syftar denna studie huvudsakligen till att undersöka om det finns samband mellan olika demografiska och socioekonomiska variabler och nivåer av risktolerans. Med hjälp av tidigare studier valdes följande variabler att undersökas: kön, ålder, utbildningsnivå, relationsstatus, sysselsättning och inkomstnivå. Som verktyg för att mäta nivåer av risktolerans valdes Grable och Lyttons 13-items risk assessment instrument, vilken har genomgått ett flertal validitetsprövningar. Då majoriteten av forskningen inom finansiell risktolerans har genomförts på den amerikanska marknaden särskiljer sig denna studie då den riktar in sig på svenska individer, från 18 år till pension. Metoden för att få in svar har varit med hjälp av en enkätstudie, både via internet och genom pappersenkäter på ett antal arbetsplatser runt om i landet. Resultatet blev totalt 206 fullständiga enkäter och stark signifikans återfanns hos kön (99 procent konfidensintervall), där män i genomsnitt hade högre risktolerans än kvinnor. Även inkomstnivå var signifikant, med ett konfidensintervall på 90 procent, men visade att sambandet inte var perfekt positivt linjärt (låg inkomst = låg risktolerans, hög inkomst = hög risktolerans). Studien syftade även till att söka övriga förklaringar och samband som risktolerans också påverkar, med hänsyn till: sparande, pensionssparande, investeringsval, framtidsutsikt för den finansiella marknaden samt förändring av investeringsbeteende på grund av de senaste årens finansiella oro.Detta resulterade i att: 13,5 procent svarade att de inte hade något som helst privat sparande; mer än hälften av individerna uppgav att de inte har något privat pensionssparande; individer med högre inkomster valde oftare aktier som främsta investeringsval än de med lägre inkomster, som föredrog sparkonton; en övervägande majoritet har inte ändrat sitt investeringsbeteende men 25 procent av respondenterna angav att de investerar mindre nu till följd de senaste årens finansiella oro på marknaden samt att 40,6 procent angav att det är mer riskfyllt med värdepapper idag; mer än hälften av respondenterna angav att de känner en viss oro inför sin framtida pension.

La presente tesis estudia la correlación negativa entre inflación y precios reales de las acciones. En primer lugar, muestro evidencia de que la inflación impone costos reales en la economía, en particular al disminuir los beneficios de las empresas, tal como sugiriera originalmente Miton Friedman. Segundo, sugiero que la inflación decrece los precios reales de las acciones dado que la probabilidad de sufrir estanflación en el futuro crece con la tasa de inflación (premio evento-extremo). Tercero, testeo si la evidencia macroeconómica respalda la relación positiva entre inflación e incertidumbre, y la relación entre inflación y el precio del riesgo (avesión relativa al riesgo). Cuarto, presento un estudio histórico, Alemania entre 1870 y 1935, para mostrar que es el premio por evento-extremo, y no illusion monetaria, lo que conlleva la correlación negativa entre inflación y precios reales de acciones. El último capítulo discute contagio en países emergentes.

Desde o trabalho de Lucas (1987), diversos autores se dedicaram a medir o custo de bem-estar dos ciclos econômicos. Embora a literatura desse tema para os Estados Unidos seja extensa, há poucos estudos para países em desenvolvimento. O objetivo do presente trabalho é estimar este custo para uma amostra de países latino-americanos e compará-lo ao custo obtido dos dados da economia dos Estados Unidos. É utilizada a metodologia proposta por Reis (2009), que assume que o consumo segue um processo ARIMA(p,1,q), que tem as ordens selecionadas com base no critério de informação bayesiano. Os resultados obtidos indicam que, sob todos os processos assumidos para as série de consumo, os países latino-americanos possuem custo consideravelmente maior do que o dos Estados Unidos. Entretanto, quando se assume a estrutura ARIMA, a diferença entre os custos dos países latino-americanos e dos Estados Unidos é a menor. / Since the work of Lucas (1987), several authors have dedicated to measure the welfare costs of business cycle. Although the literature on this subject is extensive for the United States, few studies were made considering developing countries data. The objective of this study is to estimate this cost for a sample of Latin American countries and compare it to the cost obtained from the US economy data. The methodology proposed by Reis (2009) is used. It assumes that consumption follows an ARIMA (p,1,q) model, and the p and q orders are selected based on the Bayesian information criterion. The results indicate that, in all processes assumed for the consumption series, Latin American countries have considerably higher welfare costs than the US. However, when the ARIMA structure is assumed, the difference between the costs of Latin American countries and the United States is the smallest.

Nesta tese desenvolvemos modelos de apreçamento de ativos financeiros baseados no conceito de influência social, analisamos também algumas das consequências destes modelos e comparamos com os modelos correspondentes clássicos. Por meio das funções de utilidade generalizadas exponencial e quadrática, deduzimos o CAPM com influência social. Obtivemos que o coeficiente beta da fórmula do CAPM depende de uma aversão ao risco efetiva do mercado que depende da distribuição de riqueza dos agentes do mercado. Supondo que distribuição de riqueza dos agentes do mercado segue uma distribuição de Pareto, fomos capazes de conectar, aversão ao risco média efetiva do mercado, volatilidade e distribuição de riqueza dos agentes, estabelecendo a previsão empírica de que a volatilidade aumenta com a concentração da distribuição de riqueza dos agentes do mercado, a qual foi corroborada por meio de análise estatística. Através da função generalizada tipo potência são feitas algumas considerações sobre alguns \"puzzles\" econômicos bem conhecidos (o \"Equity Premium Puzzle\" e o \"Riskfree Rate Puzzle\") que mostram que a modelagem da influência social pode ter impacto no esclarecimento destes \"puzzles\". / In this thesis we develop pricing models for financial assets based in the concept of social influence, we analyze too some of consequences of this models and we compare with the corresponding classical models. By means of the exponential and quadratic generalized utility functions, we deduce the CAPM with social influence. We obtained that the coefficient beta from the formula of the CAPM depends of a market effective risk aversion that depends of the wealth distribution of the market agents. Supposing that the wealth distribution of the market agents follows a Pareto distribution, we were able to connect, market effective average risk aversion, volatility and wealth distribution of the agents, establishing the empirical forecasting that the volatility grows with the concentration of the wealth distribution of the market agents, which was corroborated by means of statistical analysis. Through the generalized power function are made some considerations about some economic puzzles well-known (the Equity Premium Puzzle and the Riskfree Rate Puzzle) that show us that the modeling of the social influence can to have impact in the clarification these puzzles.

The paper provides an explanation of the mechanisms underlying trade roots of the contagion effects emanating from the recent turmoils. It is argued that under demand uncertainty risk averse behavior of firms provides a basis for international trade. The paper shows by means of a simple two-country model that risk averse firms operating in perfectly competitive markets with uncertainty of demand tend to diversify markets what gives a basis for international trade in identical commodities even between identical countries. It is shown that such trade may be welfare improving despite efficiency losses due to cross-hauling and transportation costs. The analysis reveals that change of the expectations concerning market conditions caused by the turmoil in the neighbor country (i.e., shift in the perception of market conditions) may lead to macroeconomic destabilization (increase in price level and unemployment, worsening of terms of trade, and deterioration of trade balance). / Series: Discussion Papers of the Institute for Economic Geography and GIScience

This compilation dissertation consists of four essays with the common theme of welfare analysis of long-term public investments. The first two essays focus on analysis of climate change mitigation, i.e., the social cost of carbon dioxide. The third essay focuses on cost-benefit analysis (CBA) of transport investment projects, while the last essay takes a broader perspective on welfare analysis. Essay 1: The Temporal Aspects of the Social Cost of Greenhouse Gases. The purpose of Essay 1 is to investigate the temporal aspects of the social cost of greenhouse gases. I find that the calculation period should ultimately be modeled to be consistent with the discount rate and that the “global-warming potential” concept is unsuitable for calculation of the social cost of GHGs other than carbon dioxide. Essay 2: Avoiding path dependence of distributional weights: Lessons from climate change economic assessments. In Essay 2, I explore shortcomings in income weighting in evaluation of climate change policy. In short, in previous versions of two of the most important existing models, regional economic growth is double counted. The proposed alternative approaches yield about 20–40% higher values of SCCO2 than the old approach. Essay 3: Does uncertainty make cost-benefit analyses pointless? In Essay 3, the aim is to investigate to what extent CBA improves the selection decision of projects when uncertainties are taken into account, using a simulation-based approach on real data of infrastructure investments. The results indicate that, in line with previous literature, CBA is a rather robust tool and considerably increases the quality of decision making compared with a random selection mechanism, even when high levels of uncertainty are considered. Essay 4: Household Production and the Elasticity of Marginal Utility of Consumption. In Essay 4, I develop a new model to show that omission of household production in a previous model leads to bias when the elasticity of marginal utility of consumption, EMUC, is estimated. I further offer new, unbiased estimates based on current evidence of the included parameters, suggesting a lower bound of EMUC at about 0.9.

Aktiemarknaden har en mängd olika teorier som förklarar hur människor agerar och hur de grundar sina beslut, de valda teorierna i studien är portföljteorin, den effektiva marknadshypotesen (EMH), beteendeekonomi, beteendeportföljteori och den adaptiva marknadshypotesen (AMH). De valda teorierna förklarar samma områden men på olika sätt, portföljteorin och EMH som säger att marknaden är effektiv och att människor är rationella. Beteendeekonomi, beteendeportföljteorin (BPT) och AMH säger istället att människor inte är rationella utan att de är normala; investerare har olika bias och agerar utifrån sina egna bedömningar. AMH skiljer sig något från beteendeekonomi och beteendeportföljteorin, men det de har gemensamt är att de förklarar investerares agerande med bland annat psykologi och beteendemönster. Syftet med studien är att undersöka hur investerare agerar, hur mycket de diversifierar och hur riskbenägna de är, sedan jämföra resultatet med vad de olika teorierna inom aktiemarknaden säger, för att kunna dra slutsatser om investerarnas agerande. Studien använder sig av tvärsnittsdesign i form av en enkät för att samla in kvantitativ data. Herfindahl-Hirscher index (HHI) kommer att användas för att mäta koncentrationen (diversifieringen) i respektive respondents portfölj. För att kunna göra regressionsanalyser och leta efter samband behövs information om vem respondenten är och hur hans/hennes bakgrund ser ut. Det är 287 respondenter som har lämnat fullständiga svar på enkäten och är underlaget för studiens empiriska resultat. Studiens resultat jämförs med vad teorierna säger om diversifiering, riskbenägenhet och självsäkerhet (overconfidence). Slutsatserna som studien kommer fram till är att de investerare som är mest självsäkra är de som är aktieägare, har studerat ekonomi, arbetar på bank och de som hellre köper aktier själv, samt att män tenderar att vara mer självsäkra än kvinnor. Ju självsäkrare investeraren är desto mer riskbenägen är han/hon, de som arbetar på bank och/eller är aktieägare är de som är mest riskbenägna. De som diversifierar mest är yngre investerare och de som studerat ekonomi, är aktieägare och/eller föredrar att handla aktier själva, vilket betyder att ju mer relevant kunskap och erfarenhet investerare har om aktier desto mer diversifierar de. Det har inte gjorts någon slutsats om vilken teori som förklarar investerarnas agerande på bästa sätt, då resultatet har kopplats och förklarats av de flesta teorierna som omfattas av studien. / The stock market has a variety of theories that explains how people act and how they base their decisions. The chosen theories in the study are portfolio theory, the efficient market hypothesis (EMH), behavioral finance, behavioral portfolio theory and the adaptive market hypothesis (AMH). The study uses cross-sectional design in the form of a survey to collect quantitative data. The purpose of the paper is to examine how investors act, how much they diversify and how risk averse they are, and then the results are compared with the theories of this thesis. The conclusions drawn by the study are that investors who own stocks are the ones that are the most confident, have studied economics, work at banks and those who prefer to buy stocks themselves, and that men tend to be more confident than women. Those who diversify most are younger investors, those who study economics, are shareholders and/or prefer to trade shares themselves, which means that the more relevant knowledge and experience investors have about stocks, the more they diversify. It has not been decided which theory best explains how investors act; most theories are rather used to clarify the results.

<p>Predmet ovog istraživanja je ponašanje donosilaca odluka u uslovima<br />neizvesnosti. Na osnovu sprovedene simulacije među subjektima i<br />dobijenih rezultata, cilj ove disertacije je da se utvrde dominantni<br />faktori prilikom poslovnog odlučivanja u uslovma kada donosiolac<br />poslovnih odluka ne raspolaže informacijama potrebnim za ispravno<br />donošenje odluka u trenucima kada njegova investicija ostvaruje<br />gubitak. Prilikom utvrđivanja sklonosti donosioca odluke u obzir je<br />uzet i pol donosioca odluke i poslovni status, kao i prethodno<br />iskazane sklonosti ka riziku.</p> / <p>The subject of this research is behavior of decision &ndash; makers in ambiguous<br />surroundings. Based on the simulation that was conducted among subjects<br />and results obtained from it, the aim of this dissertation is to establish<br />dominant factors that influence decision &ndash; making process in situations<br />where information neccesery for adequate decision &ndash; making are not<br />available to decision &ndash; makers in situations where decision &ndash; makers are<br />facing loss. Gender and employmet status were taken into consideration<br />during determination of decision &ndash; makers preferences, as well as their<br />previously exhibited risk preferences.</p>

The purpose of this study is to describe the financial risk tolerance of young swedish residents, which factors that affect their financial risk tolerance, and how their risk tolerance affects their investment behavior. Previous studies within the subject of financial risk tolerance have focused on a wider range of ages, and most of the studies have been made on an American population. This study also contributes with more factors in the same study than many previous studies. The factors included in this research are Gender, degree of education, relationship status, income, mood, birth order, future economic expectations, and financial knowledge. The research contains a quantitative study, where the data have been collected with a survey. The study has a deductive approach, which means that the study starts with theory and moves on with empiricism and hypotheses. The hypotheses have been developed from the results of earlier studies. The survey was dedicated to young Swedish residents in the ages of 18 to 30 years old. There were 123 respondents who answered the survey, which contained 24 questions. To measure the risk tolerance of young swedish residents, the Grable and Lytton’s Risk Tolerance Scale have been used. The result of the study tells us that the financial risk tolerance of young swedish residents are affected by the factors: Gender, future expectations on the stock market and financial knowledge. The study also tells us that there is a significant different in financial risk tolerance between young swedish residents who invest in stocks, compared to those who do not invest in stocks.