De flesta företag strävar i huvudsak efter att maximera värdet av sitt företag och ett sätt att öka värdet av företaget kan vara att genomföra investeringar. En viktig faktor för att lyckas med sina investeringar är att skapa en strategi och att följa denna är avgörande för att nå dit man vill. Strategier kan utformas på olika sätt, men gemensamt för alla strategier är att de måste hantera osäkerhet. Syftet med denna uppsats är att undersöka vad små- och medelstora företag upplever som osäkerhet vid investeringar samt hur företagen hanterar dessa. Valet av små- och medelstora företag grundar sig på att den största delen av tidigare forskning inom detta ämne är gjord på stora företag.   Forskningsstrategin för denna studie är explorativ, eftersom vi strävar efter att öka förståelsen kring ett delvis outforskat område. Vi har valt att avgränsa urvalet till företag inom industrisektorn i nordöstra Skåne. Studien utgörs av en kvalitativ metod, där djupgående intervjuer har genomförts med sex respondenter på olika företag. Tillsammans med respondenternas åsikter och tidigare forskning görs tolkningar av materialet vilket bidrar till skapande av slutsatser. De främsta slutsatserna som kan dras från denna uppsats är att osäkerhet vid investeringar hanteras väldigt olika beroende på företag, trots att de är verksamma inom samma sektor. Företagen använder olika typer av strategier för att hantera vad de upplever som osäkerhet, vissa i större utsträckning än andra.  Med denna uppsats önskar vi öka förståelsen för vilka osäkerheter som finns vid investeringar samt för hur denna osäkerhet kan hanteras. Vår intension är att små och medelstora företag ska, med hjälp av denna studie, kunna känna sig säkrare i sina investeringsbeslut i framtiden. Säkrare beslut leder till minskad osäkerhet och därmed ökar chanserna för lönsamma investeringar. / Most companies’ main goal is to maximize the value of their company and one way to increase the value of the company can be to invest. An important factor in order to succeed with an investment is to create a strategy and stick to it. Strategies can be structured in different ways, but what they all have in common is the need to manage uncertainties. The purpose of this thesis is to investigate what kind of uncertainty small- and medium sized enterprises experience when they invest, as well as how they manage this. Our selection of small- and medium sized enterprises is based on the fact that the majority of previous research within this particular subject investigates large companies. The research strategy in this thesis is mainly exploratory, since our goal is to increase the knowledge within this partly unexplored subject. We chose to narrow our selection down to companies within the industrial sector in the North East of Skåne. This thesis consists of a qualitative method, where in-depth interviews were conducted with six respondents from different companies. Together with the opinions from the respondents and previous research, interpretations were made which made it possible to create conclusions. The primary conclusion to be drawn from this thesis is that investment uncertainty can be managed in different ways depending on the company, even though the companies are operating within the same sector. The companies use different types of strategies in order to manage what they experience as uncertainty, although some of them use the strategies more than others. We wish to increase the understanding and the knowledge of existing uncertainties as well as how to manage these. Our intension is to help small- and medium sized enterprises feel more secure about their investment decisions in the future.  Safer decision-making results in reduced uncertainty thus increase the chances of making profitable investments.

Background: There is a general belief that value stocks, historically, have created a greater return of investment compared to growth stocks. Investors can, through key ratios, compare companies to one another and thereby gain a solid appreciation whether a company is overvalued or undervalued relative to other comparable companies. The problem for investors is how to identify these value stocks and exploit mispricing in the market. Aim: The purpose of this study is to analyze investment strategies that are based on the Price-to-Book ratio on the Swedish stock market. Completion: To meet the purpose, the study is based on a deductive foundation with a quantitative method. Two investment strategies are investigated based on the Price-to-book ratio. The first strategy sorts the material following the value of the multiple, whereas the other strategy relies on regression analysis where interest on own capital is used as an explaining variable. Results: To only look at the price-to-book ratio, in order to distinguish undervalued stocks, does not work in the Swedish stock market during the period of 31-03-04 to 31-03-2015. It can be concluded that the combination used in the developed strategy works to identify value stocks that have a significantly higher cumulative return compared to the OMX Stockholm Price Index. / Bakgrund: Det finns en övertygelse om att värdeaktier historiskt har skapat högre avkastning än tillväxtaktier. En investerare kan genom värderingsmultiplar och nyckeltal jämföra bolag med varandra och skapa sig en uppfattning huruvida ett bolag är över- eller undervärderat relativt jämförande bolag. Problematiken ligger i hur en investerare skall identifiera värdeaktier och utnyttja felprissättningar på aktiemarknaden. Syfte: Syftet med studien är att analysera investeringsstrategier baserade på multipeln Pris/Bokfört värde på den svenska aktiemarknaden. Genomförande: För att uppfylla syftet utgår studien från en deduktiv ansats med en kvantitativ metod. Två investeringsstrategier undersöks baserade på multipeln Pris/Bokfört värde. Den ena strategin sorterar materialet utefter multipelns värde och den andra strategin genomförs med hjälp av regressionsanalys där räntabilitet på eget kapital används som förklarande variabel. Resultat: Att endast utgå från Pris/Bokfört värde, för att urskilja undervärderade aktier fungerar inte på den svenska aktiemarknaden under åren 2004-2015. Det kan fastställas att kombinationen i den utvecklade strategin fungerar för att identifiera värdeaktier som har en markant högre kumulativ avkastning jämfört med OMXSPI.

This thesis, “Empirical Asset Pricing and Investment Strategies”, examines a number of topics related to portfolio choice, asset pricing, and strategic and tactical asset allocation. The first two papers treat the predictability of asset returns. Since at least the mid-1980s until quite recently, the conventional wisdom has been that it is possible to predict the return on, for example, an index of stocks. However, a series of recent papers have challenged this conventional wisdom. I answer this challenge and show that it is possible to predict returns if structural changes in the underlying economy are taken into account. The third paper examines the comovement between stocks and bonds. I show how it is possible to improve the composition of a portfolio consisting of these two asset classes by taking into account how the comovement changes over time. All three papers are self-contained and can therefore be read in any order. The first paper is entitled “Structural Breaks in Asset Return Predictability: Can They Be Explained?” Here I investigate whether predictability has changed over time and, if so, whether it is possible to tie the change to any underlying economic variables. Dividend yield and the short interest rate are often used jointly as instruments to predict the return on stocks, but several researchers present evidence that the relation has undergone a structural break. I use a model that extends the conventional structural breaks models to allow both for smooth transitions from one state to another (with a break as a special case), and for transitions that depend on a state variable other than time. The latter allows me to directly test whether, for example, the business cycle influences how the instruments predict returns. The results suggest that this is not the case. However, I do find evidence of a structural change primarily in how the instruments predict returns for large firms. The change differs from a break in that it appears to be an extended non-linear transition during the period 1993—1997. After the change, the short rate does not predict returns at all. Dividend yield, on the other hand, is strongly significant, and the return has become more sensitive to it. In the second paper, “Restoring the Predictability of Equity Returns,” I take another perspective on predictability and structural shifts. Several recent papers have questioned the predictability of equity returns, potentially implying serious negative consequences for investment decision-making. With return data including the 1990s, variables that previously predicted returns, such as the dividend yield, are no longer significant and results of out-of-sample tests are often weak. A possible reason is that the underlying structure of the economy has changed. I use an econometric model that allows for regime shifts over time as well as due to changes in a state variable, in this case the price-earnings ratio. This makes it possible to separate influences from these two sources and to determine whether one or both sources have affected return predictability. The results indicate that, first, a structural change occurred during the 1990s, and, second, that the unusually high level of price earnings in the late 1990s and early 2000s temporarily affected predictability at the 12-month horizon. In the third paper, “Coupling and Decoupling: Changing Relations between Stock and Bond Market Returns,” I investigate stock-bond comovement. The correlation between stocks and bonds has changed dramatically over the last ten years, introducing a new type of risk for portfolio managers, namely, correlation risk. I use GARCH estimates of stock volatility, simple regressions, and regime-switching econometric models to assess whether level of volatility, or changes in volatility, can be used to explain some of the changes in comovement in seven different countries. As regards volatility level, strong support is found in almost all countries to suggest that high volatility predicts lower, or negative, comovement. I argue that this can be evidence of a market-timing type of behavior. As for changes in volatility, the results are more mixed. Only for the U.S. market do I find strong support to conclude that large changes tend to coincide with lower, or negative, comovement. This could be evidence of a flight-to-quality (or cross-market hedging) type of behavior. / <p>Diss. Stockholm : Handelshögskolan, 2007</p>

År 2007-2008 inträffade finanskrisen vilket skapade oro på den finansiella marknaden. Oron återspeglades i antalet svenska aktieägare som minskade successivt fram till år 2014. Därefter fram till idag visar statistiken att svenska aktieägare blir fler för varje år som går. En förklaring är för att digitaliseringen har skapat enklare lösningar för privatpersoner att börja spara i aktier vilket ökar tillgängligheten och inflödet. Ett ökat intresse och en ökad tillgänglighet behöver dock inte innebära en ökad kunskap hos investerarna, vilket talar för att det är relevant att dels förmedla kunskap kring aktier men framförallt identifiera den bästa investeringsstrategin som kan vägleda investerare. Syftet med uppsatsen är att undersöka om värde- eller tillväxtinvestering ger högst avkastning på Stockholmsbörsen och Micro-cap under 2012-2016. Studien tillämpar en deduktiv ansats tillsammans med en kvantitativ forskningsmetod. För att kunna ta reda på den bästa investeringsstrategin på Stockholmsbörsen och Micro-cap har sekundärdata i form av nyckeltal samt kurshistorik samlats in, bearbetats och analyserats. Med hjälp av nyckeltalen P/E och P/B har aktier kunnat kategoriseras som värde- respektive tillväxtaktier. Vidare kunde portföljer skapas av respektive kategori för att sedan vara jämförbara med varandra. Resultatet visar på att investeringsstrategin värdeinvestering tenderar att prestera bäst. Värdeinvestering presterade bäst oavsett om portföljerna bestod av aktier enbart från Stockholmsbörsen eller både Stockholmsbörsen och Micro-cap. Resultatet som erhölls visade att tillväxtinvestering presterar betydligt högre avkastning än värdeinvestering oavsett börs/handelsplattform dock utsätts en investerares kapital för så pass hög risk med tillväxtinvestering att när studien riskjusterar avkastningen är det värdeinvestering som presterar bäst. / The financial crisis during 2007-2008 concerned investors internationally. The Swedish investors’ concern was reflected in the number of shareholders which decreased until 2014. From 2014 and until today the statistics shows that Swedish shareholders are increasing. One explanation could be the digitization that created solutions for investors to buy stocks more easily. But an increased availability does not necessarily mean that the knowledge also has increased. This is one of the reasons for the importance of spreading knowledge to investors and identify the best investment strategy for guidance. The purpose is to investigate the investment strategies value investing and growth investing. To find out the best investment strategy the thesis has used the two ratios P/E and P/B and historical share prices. The stocks that are included in this thesis is both from Stockholm Stock Exchange but also from Micro-cap. The thesis has used a quantitative research method when gathering all the necessary information and a deductive approach in relation to the theories. By using the presented ratios, the thesis could categories the stocks in the respective strategy. The superior investment strategy is value investing which tends to perform the best risk-adjusted return during the time 2012-2016. Value investing tends to perform the best return regardless if the portfolio contains only stocks from Stockholm Stock Exchange or both Stockholm Stock Exchange and Micro-cap. The result showed that growth investing had the most extreme returns and would have won if the result did not adjust for the risk taken.

Este trabalho investiga a utilidade e as limitações de estratégias de investimento em ações baseadas na análise de demonstrações contábeis. Inicialmente a avaliação é realizada para o conjunto total de empresas listadas na Bovespa. Na seqüência, restringe-se a investigação para os subconjuntos de empresas com alto índice PL/P (proxy de risco) ou/e com baixo BCGI (proxy de governança). De acordo com evidências apresentadas na literatura de contabilidade e finanças conjectura-se que estes grupos possuem características para que as estratégias de investimento baseadas na análise de demonstrações contábeis sejam mais úteis para a discriminação de boas e más oportunidades de investimento. As evidências encontradas apontam para uma maior utilidade da análise de balanços para a seleção de uma carteira de investimento em ações no grupo de empresas com alto PL/P e/ou baixo BCGI. Adicionalmente, incorporam-se nas análises econométricas os fatores de risco que poderiam ter relação com os resultados encontrados. Demonstra-se que a implementação da estratégia é mais realista (em termos de volume financeiro negociado das ações) para o grupo de empresas com baixo BCGI. Entretanto, há uma redução dos retornos obtidos com essa estratégia - selecionar empresas fortes financeiramente dentro do grupo de empresas com baixo BCGI - em relação à estratégia de seleção de empresas com alto PL/P e com bons indicadores financeiros. Esse resultado é consistente com a relação teórica negativa esperada entre liquidez e retorno e contribuí com a literatura para a explicação da obtenção de retornos anormais com estratégias de investimento baseadas na utilização de análise de demonstrações contábeis. / This thesis investigates the usefulness and limitations of investment strategies based on financial statement analysis. Initially I assess the usefulness of the strategy for the full sample of Brazilian public-held firms. An additional analysis considers the partition of high book-to-market (HBM) or/and poor corporate governance (CG) firms. Capital markets research in accounting and finance show evidences that permit one to posit that firms within these groups (HBM and/or poor CG) present specific features that should enhance the usefulness of financial statement analysis as an investment tool. I find evidences that the analyzed strategies significantly differentiate between winners and losers for both groups (HBM and poor CG) but not for the full sample of firms. These results confirm and expand Piotroski\'s (2000) evidences. Further I consider the possible omitted risk-factors that could explain the results obtained. I show that the practical implementation of the strategy is more realistic (regarding stock\'s trading volume) if applied for firms with poor corporate governance arrangements when compared to the HBM ones. However, the strategy returns are lower when applied to the subset of poor corporate governance firms. This evidence is consistent with the negative expected relation between liquidity and returns (Bekaert et al, 2006) and contributes to previous research (Piotroski, 2000; Mohanran, 2005) on abnormal returns obtained with financial statements analysis.

Momentum is one of the most robust anomalies in financial markets, there are two main recent explanations for this phenomenon, a behavioral-based explanation through disposition-effect (i.e., the willingness to sell \"winners\" too quickly and to hold \"losers\" for a long time) and a fund-flow based explanation. The disposition-effect explanation is centered in the convergence of the spread between the fundamental value and the observed market price (disposition-effect causes an underreaction to news that generates this spread), and the fund flows-based explanation is due to the persistence of the performance of mutual-funds (which usually keep buying winning positions and selling the losses). This master thesis compares those theories using Brazilian data (which is suitable for the strong presence of momentum). Our empirical analysis was done using Fama-MacBeth regressions with results pointing the disposition-effect explanation as the most significant, with our robustness analysis contributing positively to the main findings. / Uma das anomalias mais robustas presente nos mercados financeiros é a existência de momentum nos preços de ações, existem duas principais explicações recentes para este fenômeno: explicação comportamental através do efeito-disposição (i.e. disposição de vender ativos \"vencedores\" rapidamente e de segurar ativos \"perdedores\" por muito tempo) e explicações de fluxos de fundos de investimento. A explicação através do efeito-disposição é centrada na convergência do spread entre o valor fundamental de um ativo e o preço de mercado observado (o efeito-disposição causa uma reação branda a notícias que gera esse spread), e a explicação baseada em fluxos de fundos que se deve pela persistência da performance de fundos (que usualmente continuam comprando posições vencedoras e vendendo as perdedoras). O objetivo desta dissertação é comparar essas teorias utilizando dados brasileiros (que é adequado pela forte presença de momentum). Nossa análise empírica foi feita através de regressões de Fama-MacBeth com resultados apontando a explicação centrada no efeito-disposição como a mais significativa, com nossa análise de robustez contribuindo positivamente para nossos resultados principais.

The interest in the stock market has increased in the last couple of years whereas those who invest use all kinds of different strategies, or none at all. Some strategies are quite complicated and time consuming, while others are easier to replicate. The Magic Formula and Piotroski’s F- Score are two of the more well-known investment strategies which have been developed during the 2000s and are relatively easy to follow. The purpose of this study is to compare the performance of the two investment strategies and if they can create excess return in Denmark, Finland and Norway. In addition, the results will be compared to an earlier study made on the Swedish market, for the sake of discovering any differences between the Nordic countries when investing according to these strategies. The results displayed that both strategies outperformed the market indexes most years and that their accumulated returns were far greater than the market indexes between 2012-2021. Out of the Nordic countries, the portfolios in accordance with The Magic Formula and Piotroski’s F-Score both performed best in Norway. In all the three countries, Piotroski’s F-Score was the better-performing strategy over these nine years regarding accumulated return. However, the results only showed statistical differences between the strategies in Norway and Denmark. Regarding differences between the countries, including Sweden, the results indicate that there are only statistical differences in accumulated return between Norway and Sweden concerning The Magic Formula portfolios during 2012-2020. On the other hand, the results for the F-Score portfolios showed statistical differences in accumulated return between all countries except between Denmark and Finland. / Under senare år har intresset för aktiemarknaden ökat allt mer, där aktörerna använder sig av en mängd olika sorters strategier, eller ingen alls. Vissa strategier kan anses vara mer komplicerade och tidskrävande medan andra är enklare att följa och förstå. Den Magiska Formeln och Piotroskis F-Score är två av de mer välkända investeringsstrategierna som båda har blivit utvecklade under 2000-talet och är relativt enkla att replikera. Syftet med denna studie är att jämföra prestationen för dessa två investeringsstrategier samt om de kan generera någon överavkastning i Danmark, Finland och Norge. Resultaten kommer dessutom jämföras med en tidigare studie gjord på den svenska marknaden, för att hitta eventuella skillnader mellan de nordiska länderna när investeringar skett enligt dessa strategier. Studiens resultat visade på att båda strategierna överträffar marknadens index flera gånger under tidsperioden samt att dess ackumulerade avkastning var högre än marknadens index mellan 2012–2021. Utav alla nordiska länder presterade portföljerna baserade på Den Magiska Formeln och Piotroskis F-Score bäst i Norge, och för samtliga tre länder presterade Piotroskis F-Score bäst av strategierna gällande ackumulerad avkastning under dessa nio år. Resultaten visade dock enbart statistiska skillnader mellan strategierna i Danmark och Norge. Samtidigt visar resultatet på statistiska skillnader för ackumulerad avkastning mellan länderna Norge och Sverige gällande portföljerna enligt Den Magiska Formeln under 2012–2020. Samma period visar även på statistiska skillnader mellan alla länder förutom Danmark och Finland gällande portföljerna enligt Piotroskis F-Score.

The property market has experienced rising property values over a long period, resulting in lower yield requirements. In the spring of 2022, a war in Ukraine began that would unbalance the global financial system, resulting in high inflation and rising interest rates that significantly impacted the property market, the transaction volume fell, and prices began to fall. As a result, we wanted to understand better how directly owned real estate funds operating in Sweden are acting in their investment strategies in the face of a coming economic downturn. The report mainly used qualitative data collection, where 16 semi-structured interviews were conducted over five weeks. The results were collected and summarised together with the theory and literature review. The conclusion clarified that directly owned real estate funds operating in Sweden do not change their investment strategies significantly in the face of an upcoming economic downturn. The same applies to their investment parameters. The majority had raised capital before the shift in the market and thus committed to investing the capital according to the strategy set at that time. In contrast, real estate funds consider property segments that follow macroeconomic trends with a defensive nature as most desirable in the face of a coming economic downturn. / Fastighetsmarknaden har under en lång period upplevt stigande fastighetsvärden som resulterat i lägre avkastningskrav. Under våren 2022 inleddes ett krig i Ukraina som skulle sätta det globala finansiella systemet ur balans, vilket resulterade i hög inflation och stigande räntor som satte stor prägel på fastighetsmarknaden, transaktionsvolymen föll och fastighetspriserna började falla. Det resulterade i att vi ville få en större förståelse över hur direktägande fastighetsfonder med verksamhet i Sverige agerar i sina investeringsstrategier inför en kommande lågkonjunktur. Rapporten använde främst kvalitativ informationsinsamling där det genomfördes 16 semistrukturerade intervjuer under en femveckorsperiod. Resultaten samlades in och sammanställdes tillsammans med framförda teorier från litteraturgenomgången. Slutsatsen klargjorde att direktägande fastighetsfonder med verksamhet i Sverige inte ändrar sina investeringsstrategier avsevärt inför en kommande lågkonjunktur, detsamma gäller för deras investerings parametrar. Majoriteten har rest kapital innan skiftet på marknaden och därav ålagt sig att investera kapitalet utifrån strategin som sattes då. Däremot är det tydligt att fastighetsfonderna i sin helhet anser fastighetssegment som följer makroekonomiska trender med defensiv karaktär som mest önskvärda inför en kommande lågkonjunktur.

This thesis explores the implementation of three quantitative investment strategies – the dividend yield strategy, the EV/EBITDA strategy, and the momentum strategy – within the Swedish stock market using Equal-Weighted Portfolios (EWP) and Value-Weighted Portfolios(VWP). The analysis is based on backtesting during the periods 2009 − 2022, 2001 − 2022, and 1992 − 2022, for each strategy respectively. The research aims to assess the risk-adjusted returns of these strategies and compare the performance of the EWP and the VWP. The results indicate that all the tested quantitative investment strategies beat the market. Moreover, the VWP achieve higher annual returns compared to the EWP. However, when considering risk-adjusted returns, the EWP generally demonstrate superior performance. Specifically, the EWP incorporating momentum monthly rebalancing exhibit the largest risk-adjusted returns.

Die folgende Arbeit befasst sich mit den Untersuchungen von Problemen der Optimierung von Ressourcen in Umgebungen mit unvorhersehbarem Verhalten, wo: (i) nicht alle Informationen verfügbar sind, und (ii) die Umgebung unbekannte zeitliche Veränderungen aufweist. Diese Dissertation ist folgendermaßen gegliedert: Teil I stellt das Investitionsmodell vor. Es wird sowohl eine analytische als auch eine numerische Analyse der Dynamik dieses Modells für feste Investitionsstrategien in verschiedenen zufälligen Umgebungen vorgestellt. In diesem Investitionsmodell hängt die Dynamik des Budgets des Agenten x(t) von der Zufälligkeit der exogenen Rendite r(t) ab, wofür verschiedene Annahmen diskutiert wurden. Die Heavy-tailed Verteilung des Budgets wurde numerisch untersucht und mit theoretischen Vorhersagen verglichen. In Teil II wurde ein Investitionsszenario mit stilisierten exogenen Renditen untersucht, das durch eine periodische Funktion mit verschiedenen Arten und Stärken von Rauschen charakterisiert ist. In diesem Szenario wurden unterschiedliche Strategien, Agenten-Verhalten und Agenten Fähigkeiten zur Vorhersage der zukünftigen r(t) untersucht. Hier wurden Null-intelligenz-Agenten, die über technischen Analysen verfügen, mit Agenten, die über genetischen Algorithmen verfügen, verglichen. Umfangreiche Ergebnisse von Computersimulationen wurden präsentiert, in denen nachgewiesen wurde, dass für exogene Renditen mit Periodizität: (i) das wagemutige das vorsichtige Verhalten überbietet, und (ii) die genetischen Algorithmen in der Lage sind, die optimalen Investitionsstrategien zu finden und deshalb die anderen Strategien überbieten. Obwohl der Schwerpunkt dieser Dissertation im Zusammenhang mit dem Gebiet der Informatik präsentiert wurde, können die hier vorgestellten Ergebnisse auch in Szenarien angewendet werden, in denen der Agent anderere Arten von Ressourcen steuern muss, wie z.B. Energie, Zeitverbrauch, erwartete Lebensdauer, etc. / The main goal of this PhD thesis is to investigate some of the problems related to optimization of resources in environments with unpredictable behavior where: (i) not all information is available and (ii) the environment presents unknown temporal changes. The investigations in this PhD thesis are divided in two parts: Part I presents the investment model and some analytical as well as numerical analysis of the dynamics of this model for fixed investment strategies in different random environments. In this investment model, the dynamics of the investor''s budget x(t) depend on the stochasticity of the exogenous return on investment r(t) for which different model assumptions are discussed. The fat-tail distribution of the budget is investigated numerically and compared with theoretical predictions. Part II investigates an investment scenario with stylized exogenous returns characterized by a periodic function with different types and levels of noise. In this scenario, different strategies, agent''s behaviors and agent''s capacities to predict the future r(t) are investigated. Here, ''zero-intelligent'' agents using technical analysis (such as moving least squares) are compared with agents using genetic algorithms to predict r(t). Results are presented for extensive computer simulations, which shows that for exogenous returns with periodicity: (i) the daring behavior outperforms the cautious behavior and (ii) the genetic algorithm is able to find the optimal investment strategy by itself, thus outperforming the other strategies considered. Finally, the investment model is extended to include the formation of common investment projects between agents. Although the main focus of this PhD thesis is more related to the area of computer science, the results presented here can be also applied to scenarios where the agent has to control other kinds of resources, such as energy, time consumption, expected life time, etc.