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Creation and evaluation of information resources in medicine
Janda, Aleš ; Kasal, Pavel (advisor) ; Hendl, Jan (referee) ; Mihál, Vladimír (referee) ; Sumerauer, David (referee)
A field covering generation and evaluation of the medical information is a broad one. During my doctoral studies I focused on medical information mainly using the evidence-based medicine (EBM) principles. This approach leads to the use of currently best available medical data in the treatment of patients. The EBM methodology might be classified into two basic groups: afferent and efferent one. The afferent part is focused on development of information resources whereas the efferent one promotes optimal use of these resources and a critical application of the retrieved facts. Due to practical reasons (to limit extent of the text) I concentrated in the thesis on only one field of my activity. The text deals mainly with afferent part of EBM, namely with formation of a qualitative and quantitative synthesis of knowledge through compilation of a systematic review and meta-analysis. Compilation of systematic reviews of prognostic markers is discussed in a detail. It is a field not appropriately covered in the Czech literature. The practical outcome documented in the thesis is a description of the systematic review of immunohistochemical prognostic markers in intracranial ependymomas that was created and published by our research team. Compilation of this systematic review and meta-analysis was one of the...
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Meta-Analysis in Economics: Application to Measuring the Euro's Trade Effect
Polák, Petr ; Havránek, Tomáš (advisor) ; Havránková, Zuzana (referee)
Meta-analysis is a very strong and effective tool designed for the synthesis of results of empirical research. It provides a possibility to make reliable conclusions and offers more systematic and unbiased view at empirical studies than do narrative reviews. This thesis begins with description of meta-analysis from the theoretical point of view and, therefore, is the first Czech-written methodology of modern meta-analysis suitable for economics. This part is followed by an applied meta-analysis that investigates the euro effect on common trade exchange, and the analysis is focused on publication bias and the use of the multilevel random effects model. The empirical part is based on 2580 estimates gathered from 33 studies that investigate the relationship between euro and trade volume. The meta-analysis reveals the presence of publication bias, confirms the economic research cycle hypothesis and estimates, according to the available literature, that the true Rose effect lies probably between 2 and 6 percent.
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Price Elasticity of Water Demand: A Meta-Analysis
Thoma, Richard ; Havránek, Tomáš (advisor) ; Janotík, Tomáš (referee)
Meta-analysis is a statistical method that allows us to combine results of em- pirical research. A theoretical summary helped to select appropriate model for the empirical part of this thesis - a meta-analysis focused on the price elas- ticity of residential water demand. A mixed-effects multilevel model, which corrects for selection bias, heteroskedasticity and within-study correlation, was employed. Publication bias was found only for subsample excluding data from the western part of the United States. Heckman meta-regression shows that the true price elasticity of water demand is -0,246. Finally variation in results across studies is explained. Using average price instead of margi- nal, the discrete-continuous choice model and data from the western part of the United States for water demand modelling will result in higher values of estimated elasticity. 1
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Corporate Tax Competition: A Meta-Analysis
Labíková, Nikol ; Polák, Petr (advisor) ; Schneider, Ondřej (referee)
This thesis provides the first meta-analysis investigating the effect of corporate tax competition among states, with special focus on the effect of the corporate tax rate change in competing country on the corporate tax rate in the home country. It examines 523 estimates from 20 published studies and working papers. Results of the meta-analysis show an evidence of substantial publication selectivity: researchers tend to discard negative and insignificant estimates, which overvalues the estimated effect size. Conducted precision effect test failed to find the evidence for the existence of a genuine effect of corporate tax competition. Empirical analysis shows that differences in the measurement of statutory and effective tax rate matter, thus the analysis was conducted on two separate sub-samples. Meta-regression analysis have found significant impact of variables related to publication bias for both sub-samples. Next to it, the results provide an evidence of significant influence of politically orientated controls, especially of the variable controlling whether or not there were elections in the particular year and state in case when the corporate tax rate changed. Powered by TCPDF (www.tcpdf.org)
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Revealed preferences for outdoor recreation in natural areas - Czech and European perspective
Kaprová, Kateřina ; Melichar, Jan (advisor) ; Brůha, Jan (referee) ; Šauer, Petr (referee)
K. Kaprová (2019): Revealed preferences for outdoor recreation in natural areas - Czech and European perspective Abstract of the Doctoral Dissertation The dissertation thesis focuses on the investigation and synthesis of recreation welfare benefits associated with natural areas in the Czech Republic and in Europe. The dissertation thesis consists of five case studies. These represent various geographic levels of analysis: the level of one single recreation locality, the national level that takes into account large natural recreation sites in the Czech Republic (including protected areas), and a synthesis of results of studies on the European level. The methodological approach is based on the theory of environmental economics and employs non-market valuation techniques based on methods of revealed preferences, namely the hedonic pricing method and two types of travel cost modelling. In Study I, we examine how the presence and characteristics of urban greenery affect property prices in Prague. The results confirm that proximity to greenery and its area are important determinants of housing prices in Prague, which means that residents realize the positive values provided by urban greenery, including recreational ecosystem service. Benefits to residents differ with the type of greenery. Urban forests have the...
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The Interest Elasticity of Money Demand: A Meta-Analysis
Slouková, Eliška ; Havránek, Tomáš (advisor) ; Holub, Tomáš (referee)
Even though precise evaluation of money demand function is essential for cen- tral banking and for the right determination of the transmission mechanism, economists have not reached a consensus about the underlying determinants of money demand function neither their magnitude and direction. Researchers differ even in the selection of measures used for the main variables - income, and interest rate. While the heterogeneity in elasticity estimates of the former one has been scrutinize in several quantitative surveys, to the best of our knowledge, there has not been compiled any meta-analysis focusing on differences among the interest rate elasticities of the money demand. Therefore, we collected 53 studies reporting 1 094 estimates of interest rate elasticity. Implementing both the state-of-the-art methods and those proposed only recently, we have found out that researches are prone to selective reporting. Firstly, our results shows that negative publication bias is present in empirical studies of the money de- mand and increases the average elasticity estimate approximately three times (in absolute terms). Secondly, negative highly precise estimates are more likely to be compared to their imprecise counterparts. Additionally, we scrutinize po- tential sources of heterogeneity among individual...
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Islam and Economic Performance: A Meta-Analysis
Kratochvíla, Patrik ; Havránek, Tomáš (advisor) ; Schwarz, Jiří (referee)
Islam and Economic Performance: A Meta-Analysis Patrik Kratochvíla June 28, 2021 Abstract The ongoing economic supremacy of the West has prompted debates on the ability of non-Christian religions to generate economic growth. The academic literature focusing on the Islamic religion o↵ers multiple answers, leaving the matter unresolved and with no definite conclusion. Based on a quantitative sur- vey of 315 estimates collected from 41 relevant academic studies, Islam exerts a positive and statistically significant e↵ect on economic growth in 40% of cases, a negative and statistically significant e↵ect in 10% of cases, and virtually zero e↵ect in 50% of cases. Tests for publication bias indicate slightly preferential reporting against negative estimates. When I correct for this bias, I find that the mean e↵ect of Islam on economic growth is positive but economically small. I also construct 79 moderator variables capturing methodological heterogeneity among the primary studies and apply the method of Bayesian model averaging to deal with model uncertainty in meta-analysis. The analysis shows that the heterogeneity in the results is primarily driven by di↵erences in the sample com- position and the choice of control variables, and to a lesser extent by estimation characteristics and proxies for Islam employed. 1
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Income Inequality and Happiness: A Meta-Analysis
Kamenická, Lucie ; Havránková, Zuzana (advisor) ; Chytilová, Julie (referee)
The relationship between income inequality and happiness is central to a host of welfare policies. If higher income inequality puts people down, advocating for income redistribution from the rich to the poor could make society happier. We show, however, that this popular consensus on the relationship's direction is rather absent in the academic literature. Based on the 868 observations col- lected from 53 studies and controlling for 62 aspects of study design, we use state-of-the-art meta-analysis techniques to identify several important drivers of the efect. Unless each study gets the same weight, the literature is driven by publication bias pushing the estimates against the popular consensus. While geographical diferences dominate among the systematic infuences of the re- lationship's magnitude, the relationship is also strongly afected by various methods and data the authors use in the primary studies. Most prominently, it matters if authors control for diferent individual's characteristics, such as perceived trust in people or their health status.
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Meta-analysis of bone tumorous lesions in spinal CT data using convolutional neural networks
Nantl, Ondřej ; Jakubíček, Roman (referee) ; Chmelík, Jiří (advisor)
This bachelor thesis deals with the use of convolutional neural networks in the meta-analysis of bone tumor lesions in CT image data. The theoretical part describes the anatomy and pathology of bone tissue, machine learning, discusses the functionality of convolutional neural networks and summarizes selected existing methods for computer-aided diagnosis of vertebra bone lesions. In the practical part, various types of models using convolutional neural networks were implemented and the networks were trained on an available augmented dataset. Finally, the results of various types of models were statistically evaluated, compared with available articles and discussed.
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Essays in Empirical Financial Economics
Žigraiová, Diana ; Jakubík, Petr (advisor) ; Witzany, Jiří (referee) ; Teplý, Petr (referee) ; Gächter, Martin (referee)
This dissertation is composed of four essays that empirically investigate three topics in financial economics; financial stress and its leading indicators, the relationship between bank competition and financial stability, and the link between management board composition and bank risk. In the first essay we examine which variables have predictive power for financial stress in 25 OECD countries, using a recently constructed financial stress index. We find that panel models can hardly explain FSI dynamics. Although better results are achieved in country models, our findings suggest that financial stress is hard to predict out-of- sample despite the reasonably good in-sample performance of the models. The second essay develops an early warning framework for assessing systemic risks and predicting systemic events over two horizons of different length on a panel of 14 countries. We build a financial stress index to identify the starting dates of systemic financial crises and select crisis-leading indicators in a two-step approach; we find relevant prediction horizons for each indicator and employ Bayesian model averaging to identify the most useful predictors. We find superior performance of the long-horizon model for the Czech Republic. The theoretical literature gives conflicting predictions on how bank...
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