In this paper, the price fluctuations of Bitcoin under speculative environment is studied. It has been seen that the market trend points out an existence of a speculative bubble. Over the course of the period from 2014 to 2018, the trend in price movements of bitcoin has proved to be strongly speculative. In that regard, investors might be curious about what drivers might be instrumental in these speculative price changes.  After reviewing of NPV, it was seen that NPV is not applicable to the case of cryptocurrencies due to their nature and lack of free cash flows to base the asset valuation to some fundamental facts. Later, LPPL model is reviewed, however, that also proved to be insufficient since it does not reflect the investor speculations and inform much about price dynamics regarding behavioral finance principles. Then, some papers from the past price fluctuations of bitcoin (for the period from 2010 to 2013) was reviewed and three key variables were determined which might explain price movements. Public interest towards Bitcoin as interest-driven, regulatory and political news about cryptocurrencies as event-driven and VIX as overall investor approach to Bitcoin market have been taken. After running regressions, the only significant variable happened to be public interest and popularity of Bitcoin. Although, for some cases, VIX variable also explain price fluctuations for some intervals, in none of the cases event-driven variable has long- terms effect on price fluctuations under speculative environment. Lastly, a robustness test is also handled considering the “weekend effect” and it has been seen public interest variable again proved to be a significant price determinant.

This thesis aims to investigate to what extent the quantitative easing monetary policy tool, applied by the Riksbank, contributed to abnormal returns at the Swedish stock market during Covid-19. The chosen time period is 2007-2022, including the period before and after the implementation of quantitative easing in Sweden in 2015. Furthermore, the chosen time period includes two crises, the global financial crisis (GFC) and the Covid-19 crisis. Two artificial portfolios are created, one representing a high-risk portfolio and the other representing a low-risk portfolio. The thesis applies the ADL error correction model to estimate a potential relationship amongst QE and the returns for each of the computed portfolios. Results show a short-run relationship for both the high-risk and the low-risk portfolio. From the long-run perspective, there is only a relationship found concerning the high-risk portfolio. A modified CAPM-model is used as an interpretation when calculating abnormal returns, where the growth rate of industrial production reflects the expected return. Results show the presence of QE and abnormal returns for both portfolios during the time period of Covid-19, 2020-2022. / Denna uppsats syftar till att undersöka i vilken utsträckning Riksbankens kvantitativa lättnader bidrog till abnorm avkastning på den svenska aktiemarknaden under Covid-19. Den valdat idsperioden är 2007 – 2022, vilket inkluderar perioden före och efter genomförandet av kvantitativa lättnader i Sverige. Vidare inkluderar den valda tidsperioden två kriser, den globala finanskrisen samt Covid-19-krisen. Två artificiella portföljer konstrueras, där en representerar en högriskportfölj och den andra representerar en lågriskportfölj. Studien tillämpar en ADL error correction modell för att undersöka huruvida det existerar ett samband mellan kvantitativa lättnader och avkastningen för var och en av portföljerna. Resultaten visar ett kortsiktigt förhållande för både högrisk- och lågriskportföljen. Ur det långsiktiga perspektivet hittades endast ett samband för högriskportföljen. En modifierad CAPM-modell används vid beräkning av abnorm avkastning, där variabeln för den industriella produktionstillväxten reflekterar den förväntade avkastningen. Resultaten visar förekomsten av abnorm avkastning i samband de kvantitativa lättnader som genomfördes under Covid-19 för båda portföljerna under tidsperioden 2020–2022.

Partant du constat d’une faible connaissance et d’une utilisation encore limitée des données climatiques en économie du développement, cette thèse propose une exploitation originale à la fois macroéconomique et microéconomique des données climatiques. Elle répond à un double objectif consistant d’une part, à enrichir les connaissances concernant les données climatiques en fournissant une nouvelle base de données mondiale directement exploitable par les économistes, d’autre part, à en proposer des exploitations variées et à différentes échelles de l’économie. La première partie propose une utilisation macroéconomique des données climatiques. Elle doit permettre une meilleure appréhension des données climatiques mondiales, afin d’améliorer des connaissances sur les caractéristiques du changement climatique d’un point de vue économique. Le chapitre 1 produit une base de données climatiques disponible pour près de 200 pays au niveau mensuel pour la période 1900-2008. S’appuyant sur ce premier travail, le chapitre 2 propose une utilisation originale de la base en construisant un indicateur de vulnérabilité physique au changement climatique pouvant servir d’outil pour guider l’allocation de l’aide à l’adaptation au changement climatique. La seconde partie de cette thèse est constituée de deux études microéconomiques dont le but est d’analyser les réactions des agents face à un choc climatique. Dans ces deux chapitres, les données pluviométriques pallient le manque de données concernant la production agricole. Au niveau du ménage agricole d’abord, le chapitre 3 s’intéresse aux conséquences d’un épisode de baisse de la pluviométrie sur l’état nutritionnel des enfants de moins de cinq ans et révèle que les ménages ruraux n’ont pas la capacité d’assurer ou d’absorber ces chocs climatiques. Au niveau d’un marché céréalier ensuite, le chapitre 4 s’attache à étudier la réaction des prix face à un choc pluviométrique et met en évidence la présence d’une spéculation, particulièrement sur des marchés mal intégrés et de petite taille. / Acknowledging a limited knowledge and use of climate data in development economics, this thesis proposes a new perspective on the use of both macroeconomic and microeconomic climate data. This thesis has a two-Fold objective: to deepen knowledge on climate data through the production of a new global database directly exploitable by economists, and to propose several applications of this database at different economic scales. The first part focuses on the macroeconomic aspect of the climate data. Its aim is to empower researchers with a deeper understanding of global climate data and to increase economic knowledge on the characteristics of climate change. Chapter 1 contains a climate database available monthly over the 1900-2008 period for nearly 200 countries. Based on this initial work, Chapter 2 proposes an original use of the database with the construction of a physical indicator of vulnerability to climate change, a tool which can be used as a basis for the allocation of aid for climate change adaptation. The second part of this thesis is composed of two microeconomic studies whose aim is to analyse the behaviour of agents facing a rainfall shock. In those two chapters, rainfall data is used to compensate for the lack of data on agricultural production. At the household level, Chapter 3 focuses on the implications of an episode of reduced rainfall on the nutritional status of children under five years old. It shows that rural households do not have the capacity to provide for or absorb climate shocks. At the grain market level, Chapter 4 studies the response of prices to a shock front rainfall. It reveals the presence of speculation, especially in small and poorly integrated markets.