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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
181

Essays in economic design : information, markets and dynamics

Khan, Urmee, 1977- 06 July 2011 (has links)
This dissertation consists of three essays that apply both economic theory and econometric methods to understand design and dynamics of institutions. In particular, it studies how institutions aggregate information and deal with uncertainty and attempts to derive implications for optimal institution design. Here is a brief summary of the essays. In many economic, political and social situations where the environment changes in a random fashion necessitating costly action we face a choice of both the timing of the action as well as choosing the optimal action. In particular, if the stochastic environment possesses the property that the next environmental change becomes either more or less likely as more time passes since the last change (in other words the hazard rate of environmental change is not constant over time), then the timing of the action takes on special importance. In the first essay, joint with Maxwell B Stinchcombe, we model and solve a dynamic decision problem in a semi-Markov environment. We find that if the arrival times for state changes do not follow a memoryless process, time since the last observed change of state, in addition to the current state, becomes a crucial variable in the decision. We characterize the optimal policy and the optimal timing of executing that policy in the differentiable case by a set of first order conditions of a relatively simple form. They show that both in the case of increasing and decreasing hazard rates, the optimal response may be to wait before executing a policy change. The intuitive explanation of the result has to do with the fact that waiting reveals information about the likelihood of the next change occurring, hence waiting is valuable when actions are costly. This result helps shed new light on the structure of optimal decisions in many interesting problems of institution design, including the fact that constitutions often have built-in delay mechanisms to slow the pace of legislative change. Our model results could be used to characterize optimal timing rules for constitutional amendments. The paper also contributes to generalize the methodology of semi-Markov decision theory by formulating a dynamic programming set-up that looks to solve the timing-of-action problem whereas the existing literature looks to optimize over a much more limited set of policies where the action can only be taken at the instant when the state changes. In the second essay, we extend our research to situations, where the current choice of action influences the future path of the stochastic process, and apply it to the legal framework surrounding environmental issues, particularly to the ‘Precautionary Principle' as applied to climate change legislation. We represent scientific uncertainty about environmental degradation using the concept of 'ambiguity' and show that ambiguity aversion generates a 'precautionary effect'. As a result, justification is provided for the Precautionary Principle that is different from the ones provided by expected utility theory. This essay serves both as an application of the general theoretical results derived in the first essay and also stands alone as an analysis of a substantive question about environmental law. Prediction markets have attracted public attention in recent years for making accurate predictions about election outcomes, product sales, film box office and myriad other variables of interest and many believe that they will soon become a very important decision support system in a wide variety of areas including governance, law and industry. For successful design of these markets, a thorough understanding of the theoretical and empirical foundations of such markets is necessary. But the information aggregation process in these markets is not fully understood yet. There remains a number of open questions. The third essay, joint with Robert Lieli, attempts to analyze the direction and timing of information flow between prices, polls, and media coverage of events traded on prediction markets. Specifically, we examine the race between Barack Obama and Hillary Clinton in the 2008 Democratic primaries for presidential nomination. Substantively, we ask the following question: (i) Do prediction market prices have information that is not reflected in viii contemporaneous polls and media stories? (ii) Conversely, do prices react to information that appears to be news for pollsters or is prominently featured by the media? Quantitatively, we construct time series variables that reflect the "pollster's surprise" in each primary election, measured as the difference between actual vote share and vote share predicted by the latest poll before the primary, as well as indices that describe the extent of media coverage received by the candidates. We carry out Granger Causality tests between the day-to-day percentage change in the price of the "Obama wins nomination" security and these information variables. Some key results from our exercise can be summarized as follows. There seems to be mutual (two-way) Granger causality between prediction market prices and the surprise element in the primaries. There is also evidence of one-way Granger causality in the short run from price changes towards media news indices. These results suggest that prediction market prices anticipate at least some of the discrepancy between the actual outcome and the latest round of polls before the election. Nevertheless, prices also seem to be driven partly by election results, suggesting that there is an element of the pollster’s surprise that is genuine news for the market as well. / text
182

Oscillatory Network Activity in Brain Functions and Dysfunctions

Adhikari, Bhim M 10 May 2014 (has links)
Recent experimental studies point to the notion that the brain is a complex dynamical system whose behaviors relating to brain functions and dysfunctions can be described by the physics of network phenomena. The brain consists of anatomical axonal connections among neurons and neuronal populations in various spatial scales. Neuronal interactions and synchrony of neuronal oscillations are central to normal brain functions. Breakdowns in interactions and modifications in synchronization behaviors are usual hallmarks of brain dysfunctions. Here, in this dissertation for PhD degree in physics, we report discoveries of brain oscillatory network activity from two separate studies. These studies investigated the large-scale brain activity during tactile perceptual decision-making and epileptic seizures. In the perceptual decision-making study, using scalp electroencephalography (EEG) recordings of brain potentials, we investigated how oscillatory activity functionally organizes different neocortical regions as a network during a tactile discrimination task. While undergoing EEG recordings, blindfolded healthy participants felt a linear three-dot array presented electromechanically, under computer control, and reported whether the central dot was offset to the left or right. Based on the current dipole modeling in the brain, we found that the source-level peak activity appeared in the left primary somatosensory cortex (SI), right lateral occipital complex (LOC), right posterior intraparietal sulcus (pIPS) and finally left dorsolateral prefrontal cortex (dlPFC) at 45, 130, 160 and 175 ms respectively. Spectral interdependency analysis showed that fine tactile discrimination is mediated by distinct but overlapping ~15 Hz beta and ~80 Hz gamma band large-scale oscillatory networks. The beta-network that included all four nodes was dominantly feedforward, similar to the propagation of peak cortical activity, implying its role in accumulating and maintaining relevant sensory information and mapping to action. The gamma-network activity, occurring in a recurrent loop linked SI, pIPS and dlPFC, likely carrying out attentional selection of task-relevant sensory signals. Behavioral measure of task performance was correlated with the network activity in both bands. In the study of epileptic seizures, we investigated high-frequency (> 50 Hz) oscillatory network activity from intracranial EEG (IEEG) recordings of patients who were the candidates for epilepsy surgery. The traditional approach of identifying brain regions for epilepsy surgery usually referred as seizure onset zones (SOZs) has not always produced clarity on SOZs. Here, we investigated directed network activity in the frequency domain and found that the high frequency (>80 Hz) network activities occur before the onset of any visible ictal activity, andcausal relationships involve the recording electrodes where clinically identifiable seizures later develop. These findings suggest that high-frequency network activities and their causal relationships can assist in precise delineation of SOZs for surgical resection.
183

Money Supply Behavior in ‘BRICS’ Economies : - A Time Series Analysis on Money Supply Endogeneity and Exogeneity

LUO, PENGCHENG January 2013 (has links)
This thesis investigated money supply behaviors in the ‘BRICS’ group from 1982 to 2012. It empirically analyzed causality relationships between related monetary indicators by using quarterly data and time series econometric methods. In four countries: Brazil, China, Russia (the period of 2004-2012) and South Africa (1982-1993), this study found money supply endogeneity evidence (bank loans cause the money supply, or there is bidirectional between these two). Other countries, India and the 1982-2003 period of Russia, money supply was found to be exogenous, i.e. money supply cause bank loans. Nonetheless, traditional Monetarian view still holds across the five economies in the short run. The findings reflected discretionary monetary policies targeting monetary aggregates in the short term, despite a neutral role of most central banks in the long run.
184

能源價格衝擊與台灣總體經濟 / Energy price shocks and Taiwan’s macroeconomy

陳虹均, Chen, Hung Chun Unknown Date (has links)
自1970年代以來有許多研究指出,能源價格衝擊對於一個國家的總體經濟表現有顯著的影響。但對於能源價格究竟是以何種形式,以及透過什麼管道對總體經濟產生影響,卻沒有一致的看法。同時,經濟決策者對於能源價格變動的反應,經常因為有不確定性的存在而有延後反映的現象。本文利用台灣1981年到2009年的能源價格,建構數種對稱與不對稱之能源價格變動設定,以Granger因果關係檢定探討能源價格變動與台灣其他相關的總體經濟變數資料間的關係;並透過自我迴歸分配落後模型 (Autoregressive Distributed Lag Model, ARDL) 模型估計能源價格與台灣產出的長期關係。我們的實證結果顯示:能源價格,相較於台灣的總體經濟體系,具有外生性。能源價格成長率對產出與失業率沒有顯著的影響;但能源價格的波動程度對台灣產出成長率卻有顯著的負面影響。能源價格波動率與台灣實質產出具有長期均衡關係,而且能源價格波動將對台灣實質產出有負面影響。 / Since the 1970s, numerous studies have demonstrated that energy price impact can have a significant influence on a country’s macroeconomy. However, there is no consensus regarding in what form, or by which channel can energy price changes affect the macroeconomy. In addition, economic decision makers often respond to energy price changes with a time lag due to the existence of uncertainty. This paper constructs several indicators of symmetric and asymmetric energy price changes based on the energy prices in Taiwan for the period from 1981 to 2009. We employ the Granger’s causality test to examine the relationship between energy price changes and related macroeconomic variables; and utilize the autoregressive distributed lag model (ARDL) to estimate the long-run relationship between energy price volatility and Taiwan’s real GDP. Our empirical results show that energy price exhibits exogeneity relative to important macroeconomic variables; the energy price growth rate does not have significant impact on output and unemployment rate, while the energy price volatility has negative impact on Taiwan’s macroeconomy. There is long-run relationship between the energy price volatility and Taiwan’s real GDP. Furthermore, the energy price volatility do have negative impact on Taiwan’s real GDP.
185

T-REITs與總體經濟及商用不動產市場關聯性之探討 / The Relationship Among T-REITs, Macroeconomy and Commercial Real Estate Markets

侯蔚楚 Unknown Date (has links)
台灣不動產投資信託(T-REIT)自2005年發行至今已逾四年,過去國內相關的文獻多集中於法律面、制度架構及問卷調查等相關研究,對於整體市場實際表現的討論則較缺乏。隨著交易歷史資料的延展,本研究針對國內REITs施行的現況與總體經濟波動及不動產市場之關係進行討論。在總體經濟部分以股價指數、利率與通貨膨脹進行分析,在不動產市場部分則採用辦公室平均租金水準與實際商辦交易價格為指標,期望探索T-REITs價格與總體經濟及不動產市場間之長期關係。 本文發現T-REITs與股價指數、商辦租金以及商辦交易價格間,均會存在長期均衡關係,即有共整合情形,而T-REITs與通貨膨脹率以及T-REITs與利率間不具有長期均衡關係,且股價指數、商辦租金以及通貨膨脹率與T-REITs為正向關係,利率及商辦租金與T-REITs則為反向關係。此外,根據因果關係檢定,股價指數與通貨膨脹率皆領先T-REITs,而商辦租金與T-REITs為雙向回饋。本文結果顯示,台灣REITs與總體經濟及商用不動產市場具有長期均衡關係,亦即總體經濟的變動以及不動產市場的波動可做為探討T-REITs長期變化的指標。 / Taiwan launched the first Real Estate Investment Trusts (T-REITs) in 2005. However, over the past few years, studies regarding T-REITs mainly focused on legal system, institutional framework and questionnaire surveys, but lack of empirical analysis on the performance of T-REIT markets. This study therefore intends to explore the cointegration and causality relationship among the T-REITs, macroeconomy and commercial real estate markets. The macroeconomic factors in this study include the stock prices, interest rate and inflation rate; and the real estate variables include the commercial rents and commercial prices. Empirical results first demonstrate that there exists the long-run relationship among T-REITs, stock prices, commercial rents and commercial prices, but not the interest rate or inflation rate. Moreover, T-REITs are significantly related to stock prices, interest rate and inflation rates as well as commercial rents and commercial prices. Third, the changes of stock prices and inflation rate lead the change of T-REITs. Finally, there is a significant feedback relationship between T-REITs and commercial rents.
186

Indicadores antecedentes de atividade industrial no Brasil

Campelo Junior, Aloísio 01 October 2008 (has links)
Submitted by Aloisio Campelo Jr. (aloisio.campelo@fgv.br) on 2008-09-26T17:39:46Z No. of bitstreams: 1 Indicadores antecedentes de atividade industrial no Brasil.pdf: 484897 bytes, checksum: aee2d45f0557f2b008f036a2b7e27c0b (MD5) / Approved for entry into archive by Francisco Terra(francisco.terra@fgv.br) on 2008-10-01T12:19:55Z (GMT) No. of bitstreams: 1 Indicadores antecedentes de atividade industrial no Brasil.pdf: 484897 bytes, checksum: aee2d45f0557f2b008f036a2b7e27c0b (MD5) / Made available in DSpace on 2008-10-01T12:19:55Z (GMT). No. of bitstreams: 1 Indicadores antecedentes de atividade industrial no Brasil.pdf: 484897 bytes, checksum: aee2d45f0557f2b008f036a2b7e27c0b (MD5) / Esta dissertação apresenta diferentes metodologias de construção de indicadores antecedentes compostos de atividade econômica comparando os resultados obtidos por cada de acordo com seu poder de antecipação dos movimentos cíclicos da indústria brasileira. Entre as metodologias testadas incluem-se: i) a tradicional, proposta pelo National Bureau of Economic Research (NBER) na década de 60, adaptada e melhorada ao longo dos anos por instituições como a OCDE, The Conference Board e outros; ii) a seleção de variáveis por meio de testes de causalidade de Granger, e iii) seleção e pesos determinados por meio de regressão múltipla. A qualidade dos indicadores antecedentes compostos criados foi avaliada fora da amostra, com base na sua capacidade em antecipar, de forma regular e estável, os pontos de reversão do ciclo de crescimento da indústria brasileira e levando em consideração a conformidade cíclica geral em relação à variável de referência.
187

Transmisní mechanismus měnové politiky Federálního rezervního systému / Transmission mechanism of Monetary Policy of the Federal Reserve System

Petříková, Eva January 2008 (has links)
This thesis analyses the chief relations inside the transmission mechanism of the monetary policy of the U.S. Federal Reserve System during the period from 1955 to 2007. The theoretical part of the thesis describes the principles of the history of Federal Reserve and his monetary policy, the development of Fed's monetary policy and its transmission mechanism, the lags in the monetary policy and various theories which deal with try to explain the monetary policy relations. In the analytical part I focus on answering the most laid questions whether, how much and for how long do the nominal interest rates and monetary aggregates affect the real variables (mainly the real domestic product) of the United States. Next I focus on investigating the monetarist assumption of money neutrality in the long run. I also introduce Granger causality and Impulse and Responses investigations into proposed VAR model.
188

Alternatívne metódy odhadu potencionálného produktu a produkčnej medzery: odhad pre Česko / Alternative methods of estimating potential output and the output Gap: An application to Czech

Krasnovský, Pavol January 2009 (has links)
The text discusses some used methods for estimating potential product and output gaps based on aggregated data for the Czech Republic. Though these methods exhibit some common features, an empirical comparison demonstrates that the various techniques differ substantially. In particular, the correlation of output gaps calculated with different methods is generally low , the methods imply different turning points. To conclude, the methods for estimating potential product a used have only limited information content for macroeconomics.
189

Testování neoklasického modelu migrace: Empirická analýza panelových dat ČR / Testing the neoclassical migration model: An empirical analysis based on panel data for the Czech republic

Kureková, Lucie January 2013 (has links)
In this paper is tested validity of the neoclassical migration model. For this purpose, were used Fixed effects model and VAR model. Data contain period of years 2001 to 2010 from 14 regions of the Czech republic and dataset contains 140 observations. Empirical results of Fixed effects model show that socioeconomic determinants had signifficant influence on regional rate of migration in the Czech republic. The direction and strength of influence of the most explanatory variables corresponded to the neoclassical theory. Estimations of VAR model indicate that regional migration did not decrease disparities within regions. These results questioned validity of neoclassical migration model.
190

Hedgeové fondy a jejich vliv na stabilitu finančních trhů / Hedge Funds and Their Impact on Financial Markets

Jeřábek, Tomáš January 2016 (has links)
The aim of this PhD thesis is to analyze the history and current situation of hedge funds and assess their potential to destabilize financial markets. The findings of the analysis are used to validate the assumptions underlying the major regulatory changes of hedge funds in the key global economic centres after the financial crisis in 2008 and 2009. Since their inception early last century hedge funds have gone through a period of great expansion in the sixties, followed by a decline due to large losses sustained in the early seventies. The nineties meant a real breakthrough for hedge funds as a result of which they became prominent players in the alternative investment space. As of today, there is over ten thousand hedge funds that globally manage close to 3 trillion US dollars. Compared to mutual funds and other financial institutions the volume of assets under management is still relatively small, the rate of growth over the past fifteen years has however been very significant. What is emphasized with respect to the impact of hedge funds on financial markets is the contribution to increasing the liquidity and efficiency and their role on the financial derivatives market where hedge funds are actively involved in the transfer of risk. They are at the same time subject of criticism for their purported destabilizing effect on financial markets and contribution to fluctuations in the prices of investment instruments. Although the share of hedge funds in triggering major financial crises has not been conclusively established, these investment entities were one of the targets of the wide-ranging regulatory changes following the financial crisis of 2008 and 2009. The dissertation first discusses the history and current situation of hedge funds and defines the term hedge fund. The following section describes the basic characteristics and principles of their functioning and reviews the regulation in the major domiciles. The final chapter is focused on the empirical analysis of the impact of hedge funds on financial markets. The inputs for this analysis include a global hedge fund index and representative market indices and data from the CFTC on positions in the 10 year US government treasury note futures. In the first step the descriptive statistics for the transformed time series are presented. The second part of the analysis focuses on lagged correlations between returns and volatility of the global hedge fund index and representative market indices. Granger causality tests are applied in the following section to determine the relationships between the returns and volatility of hedge fund and representative market indices. In the final step of the analysis Granger causality tests are used to analyze the link between the changes in positions in the 10-year US treasury note futures held by hedge funds and the change in settlement prices of these futures with the aim to assess whether hedge funds have the capacity to move the market. In conclusion, the results of this analysis are discussed in light of the recent regulatory changes and the potential for the future growth of hedge funds is assessed.

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