Visual attention improves sensory processing, as well as perceptual readout and behavior. Over the last decades, many proposals have been put forth to explain how attention affects visual neural processing. These include the modulation of neural firing rates and synchrony, neural tuning properties, and rhythmic, subthreshold activity. Despite the wealth of knowledge provided by previous studies, the way attention shapes interactions between cortical layers within and between visual sensory areas is only just emerging. To investigate this, we studied neural signals from macaque V1 and V4 visual areas, while monkeys performed a covert, feature-based spatial attention task. The data were simultaneously recorded from laminar electrodes disposed normal to cortical surface in both areas (16 contacts, 150 μm inter-contact spacing). Stimuli presentation was based on the overlap of the receptive fields (RFs) of V1 and V4. Channel depths alignment was referenced to laminar layer IV, based on spatial current source density and temporal latency analyses. Our analyses mainly focused on the study of Local Field Potential (LFP) signals, for which we applied local (bipolar) re-referencing offline. We investigated the effects of attention on LFP spectral power and laminar interactions between LFP signals at different depths, both at the local level within V1 and V4, and at the inter-areal level across V1 and V4. Inspired by current progress from literature, we were interested in the characterization of frequency-specific laminar interactions, which we investigated both in terms of rhythmic synchronization by computing spectral coherence, and in terms of directed causal influence, by computing Granger causalities (GCs). The spectral power of LFPs in different frequency bands showed relatively small differences along cortical depths both in V1 and in V4. However, we found attentional effects on LFP spectral power consistent with previous literature. For V1 LFPs, attention to stimuli in RF location mainly resulted in a shift of the low-gamma (∼30-50 Hz) spectral power peak towards (∼3-4 Hz) higher frequencies and increases in power for frequency bands above low-gamma peak frequencies, as well as decreases in power below these frequencies. For V4 LFPs, attention towards stimuli in RF locations caused a decrease in power for frequencies < 20 Hz and a broad band increase for frequencies > 20 Hz. Attention affected spectral coherence within V1 and within V4 layers in similar way as the spectral power modulation described above. Spectral coherence between V1 and V4 channel pairs was increased by attention mainly in the beta band (∼ 15-30 Hz) and the low-gamma range (∼ 30-50 Hz). Attention affected GC interactions in a layer and frequency dependent manner in complex ways, not always compliant with predictions made by the canonical models of laminar feed-forward and feed-back interactions. Within V1, attention increased feed-forward efficacy across almost all low-frequency bands (∼ 2-50 Hz). Within V4, attention mostly increased GCs in the low and high gamma frequency in a 'downwards' direction within the column, i.e. from supragranular to granular and to infragranular layers. Increases were also evident in an ‘upwards’ direction from granular to supragranular layers. For inter-areal GCs, the dominant changes were an increase in the gamma frequency range from V1 granular and infragranular layers to V4 supragranular and granular layers, as well as an increase from V4 supragranular layers to all V1 layers.

This thesis aims to explore the time variation of liquidity and transaction prices in the Swedishcommercial real estate market. The purpose is to contribute with insights about price dynamics and liquidity on the Swedish commercial real estate transaction market. A price index was therefore estimated based on the output of a hedonic regression model. The model controls for different locations, segments and years and further includes variables controlling for size, portfolio transactions and investor nationality. The regression model is based on transaction data provided by Cushman & Wakefield which consists of 10 194 observations over a 20-year period between the years 2003-2023. Further the relationship between transaction prices and liquidity was investigated. The liquidity measure used is turnover rate which was calculated for each year based on data from Statistics Sweden (SCB). Granger causality tests were conducted for different geographic aggregation levels to explore if liquidity can predict transaction prices and vice versa. The results show that market liquidity in terms of turnover rate in city and regional locations can be used to forecast the development of transaction prices and therefore“leads” the price development. The test results, in combination with a correlation analysis that showed strong correlation between prices and previous year’s turnover rates, suggests evidence of a sequential relationship between the variables. For the nation as a whole and for the rural location, the results of the causality tests were insignificant and the hypothesis that there does not exist a Granger causality between price and turnover could not be rejected. It was also concluded that since liquidity leads prices, information about turnover rates can be used to help forecast property cycles in the short term. / Detta examensarbete syftar till att undersöka sambandet mellan likviditet och transaktionspriser på den svenska kommersiella fastighetsmarknaden. Syftet är att bidra med insikter om prisdynamik och likviditet på den svenska kommersiella fastighetstransaktionsmarknaden. Ett prisindex estimerades baserat på en hedonisk regressionsmodell. Modellen estimerar transaktionspriser för olika geografiska delmarknader, segment och år och inkluderar vidare variabler som kontrollerar för storlek, portföljtransaktioner och investerarnationalitet. Regressionsmodellen är baserad på transaktionsdata från Cushman & Wakefield som består av 10 194 observationer under en 20-årsperiod mellan åren 2003 och 2023. Vidare undersöktes sambandet mellan transaktionspriser och likviditet. Likviditetsmåttet som används är omsättningsandel som beräknats för respektive år baserat på data från SCB. Test av Grangerkausalitet genomfördes för olika geografiska delmarknader för att undersöka om likviditet kanprediktera transaktionspriser och vice versa. Resultaten visar att marknadslikviditet i form avomsättningsandel i storstäder och regioner kan användas för att prognostisera utvecklingen avtransaktionspriser och därmed "leder" prisutvecklingen. Testresultaten, i kombination med enkorrelationsanalys som visade på en stark korrelation mellan priser och föregående årsomsättningsandelar, tyder på att det finns ett sekventiellt samband mellan variablerna. För landet som helhet och för landsbygden gav kausalitetstesterna inget signifikant resultat och hypotesen att inget kausalitetssamband existerar mellan likviditet och priser kunde därmed inte förkastas. En annan slutsats som drogs var att eftersom likviditet leder priserna kan information om omsättningsförändring användas för att prognostisera fastighetscykler på kort sikt.

This dissertation explored the efficacy of the new Basel III banking standards in SACU, grounded on the conjecture that they are not reflective of economies of SACU, but are merely an intensification of Basel II, rather than a substantial break with it. Firstly, loans and assets were tested for causality, since Basel III believes growth in these variables led to securitization. The leverage ratio has been introduced in Basel III as an anti-cyclical buffer. The OLS technique was employed to test for its significance in determining growth in bank assets. SACU feels the impact of debt, with credit is marginally treated in Basel III and is not introspective of the realities of its economies. ANOVA tests using debt, credit and GDP were done to determine a better method of addressing cyclicality. The leverage ratio was insignificant in Namibia, with debt and credit having momentous impacts on GDP in SACU. / Economics / M. Com. (Economics)

The question in the study is to what extent the Swedish Real estate sector index acts as a follower of larger and broader stock indexes, and to what extent the index follows the asset values owned by the real estate companies in the asset market? The study is interesting for those trying to understand the development of share values in the Swedish real estate market as well as for those interesting in the “efficient market hypothesis”. The study makes an econometric analysis of the relationship between OMXS30, OMXS Real Estate PI, and the asset value of properties owned by Swedish real estate companies. Indexes are compared with Vector Autoregression (VAR) lag models, tested for dependence of GDP, the repo rent, and inflation. A Granger causality test is also performed. Despite discussed problems with reliability of some tests, the study finds that OMXS30 Granger cause OMX Real Estate PI. The study also finds that, during the period studied, OMXS30 and OMX Real Estate PI develop differently in the initial period but later form a similar path of performance. The asset values of the companies in the real estate market are more strongly correlated with OMXS30 than with their own sector index, OMXS Real Estate PI. No significant effects are found from GDP, the repo rent or inflation on OMXS30 or OMXS Real Estate PI. This may be seen as surprising but follows results from earlier studies.

論文摘要 本論文由兩篇獨立的文章所構成，第一篇文章從個體角度出發，探討臺灣產業出口與成長之間的關聯性；第二篇文章則以總體的角度，分析世界各主要國家經濟成長的型態(包括出口偏向型的成長與進口偏向型的成長)對該國貿易條件的影響。 長久以來，出口與產出之間的相互影響向來是廣受重視的議題。在國際經濟領域中，多數研究均專注於兩者間理論之建立，關於實證方面的探討並不多見，而個體角度來探討產業出口與成長之間的文獻更是稀少，以臺灣產業出口與成長之間因果關係為對象的研究則付之闕如。臺灣的經濟成就向來被歸功於出口擴張政策的成功，但出口導向的影響範圍究竟擴及多少產業的效果仍不明朗，因此第一篇文章關心的重點，在於探討對我國的產業而言出口擴張是否是個有效的政策？而究竟出口導向和產出導向哪一種政策的效果較好，也是本文所關心的目標。 第二篇文章討論成長型態對貿易條件的影響。由於出口偏向型的成長會使本國願意以更多出口財來換取進口財，將會使本國出口財的國際價格相對下降，進而惡化本國的貿易條件，改善外國的貿易條件；反之，在進口偏向型成長的情況下，出口財的減少則會使本國貿易條件改善，外國貿易條件惡化。是以一國的經濟成長對該國貿易條件的影響，將取決於其生產可能曲線外移的方向。本文嘗試以八個工業化國家和七個開發中國家為對象，在加入成長偏向政策、物價、匯率、所得移轉、對外投資、貿易平衡、貿易開放程度等因素的考慮下，來驗證成長型態對其貿易條件的影響效果是否符合理論的規範。 / The purpose of first paper is to investigate the empirical relationships between exports and domestic production in 22 Taiwan main industries, using time series data for the period 1982:01~2002:07. Different from the previous literatures, this paper examines the relations by taking into account industrial data because we are wondering whether the causal links between exports and outputs still sustain in individual industry, and either export promotion or production-led policies are more effective for industrial production. Hence, three related topics will be discussed: to recognize the incidence of export promotion policy in Taiwan industries, to explore either export promotion or production-led policies is more effective for industrial production, and to detect whether all exportation-oriented industries would simultaneously support export promotion hypothesis. The findings of the econometric analysis employing Granger causality test do not have enough evidence to support that the proportion of exports to production is a necessary condition for generating export promotion. Nevertheless, this study suggests that production makes great influence on exports in Taiwan individual industry but the effects of exports on production is not so prevailing as we thought before. Therefore, the influence of production to exports in Taiwan industry is more prevalent than that of exports to outputs. The purpose of the second paper is to examine the impacts of growth types on terms of trade by making a comparison between 8 industrial countries and 7 developing countries (involving 3 NICs countries). This paper finds that the theories seems not be supported because evidence shows the occurrence of positive effects of export-biased growth to terms of trade are more prevalent than negative ones. Moreover, the empirical results of negative incidence shown by import-biased growth come into conflict with theories, and the impacts of import-biased growth on terms of trade are indefinite. In addition, most results reveals that export-biased growth and import-biased growth policies in industrial countries are invalid, and most results in NICs and developing countries are ambiguous while export-biased growth or import-biased growth policies are adopted. Furthermore, the empirical results reveal that income transferring have great or opposite influence in NICs and developing countries, and trade openness is advantageous to NICs and developing countries but is disadvantageous to developed ones.

台灣房地產景氣動向季報的發佈不但為台灣房地產市場該季景氣狀況提供一客觀參考依據，且對未來房地產市場景氣走向進行預測分析，提供房地產景氣相關資訊予社會各界參考。在對未來房地產景氣進行預測方面，是採用領先指標作為一參考標的，雖然領先指標就其特性而言為一預測未來景氣動向的參考資訊，但卻無法明確指出其所預測的期間為多長，本研究所欲探討的部分即在於使用房地產景氣綜合指標之領先指標於預測房地產景氣上可以預測幾季之後的房地產景氣狀況，並探討房地產景氣預測的準確度。另外對廠商景氣預測的部分進行一致性的檢視，再從而比較廠商景氣認知與同時、領先指標之間的關係。希望藉此能釐清房地產景氣季報內的訊息內涵。 本研究透過因果關係檢定，找出領先指標領先同時指標三季的關係，確定可以透過領先指標來預測三季之後的景氣變化情形。再利用平均絕對百分比誤差分析使用領先指標作為預測工具的準確度，經過計算求得平均絕對百分比誤差為4.57%，可以看出使用領先指標作為預測工具相當合適。在廠商本身預測景氣動向上，本研究發現廠商預期符合調適預期理論，且對未來的預期有較為樂觀的趨勢；經過本研究統計整理發現廠商對房地產景氣變動的認知與同時指標的變動之間的一致性並不理想，此有可能是因為市場上各項房地產資訊充斥，廠商並不全然以同時指標的變動來判斷房地產景氣的變動。惟經過前後期的比較，可以發現一致性的上升與不一致性的下降，表示兩者之間認知的一致性有逐漸提升的趨勢。 / The atmosphere of the real estate industry in Taiwan was upswing gradually in the past few decades, and its market information was definitely occupied an significant role and many people started to put their focus on it. In fact, the industry forecast which can be found from those seasonal report was a prediction only that is not accurate, i.e. those projections were based on the current market information only. Therefore, how to interpret and digest the number from those reports is the crucial issue for the reader to think and to consider. This study is trying to find out the time-lags between leading index and coincident index and the accuracy of the cycle forecasting system. The Granger causality test is widely used to examine the time-lags between the leading index and the coincident index. From the result of this study, we can found that there has a 3-season time-gap embedded in, and this is an obvious difference indeed. In addition, the forecasted index of the leading indicator i.e. The MAPE is in 4.57% sharp. Thus, we dare to judge that the result of this study is absolutely accurate with 100% confidence.

封閉型基金的掛牌買賣價格，與其投資標的淨資產價值（NAV, net asset value）間，總是存在一定程度的差距，且幾乎為10%~20%的折價現象，被視為財務學上的一種異常（anomaly）。早期研究學者們由經濟理性的角度解釋此種現象，認為是基金管理的績效表現、投資標的流動性或是稅制上的差異等等角度來解釋此一現象，但並沒有獲得一致的結論。 近期以來，有學者嘗試從行為財務學的角度，認為封閉型基金的折溢價現象及其幅度的變化，是由於投資人情緒（investor sentiment）的波動所造成。除了傳統的迴歸模式，更有不少學者以嚴謹的計量方式分析，例如財務時間序列的許多技巧。本研究即以時間序列之單根檢定（unit root test）、共整合現象檢定（co-integration test）及Granger因果關係檢定（Granger Causality test）等等方式，分析封閉型基金折溢價現象是否由投資人情緒所造成，及其兩者間是否有共整合現象。 雖然已有部分文獻探討類似議題，但跨國比較分析通常僅限於英、美兩國，且英、美兩國市場連動程度太高，可能影響分析結果的正確性；除此之外，樣本分析期間亦通常不超過十年。本研究以1991-2005年英國掛牌之封閉型基金為研究樣本，並包含投資標的為日本的封閉型基金，進行英國、日本之間的跨國性比較；不但有更足夠的樣本時間長度，亦能驗證是否不同跨國分析亦會有相同結論。 共整合現象檢定及Granger因果關係檢定大致支持行為財務學的角度。但英國、日本跨國比較的結果，似乎並不完全等同於前述英、美跨國比較的結果。建議後續可從掛牌國與投資標的區域連動程度較低的封閉型基金作為研究方向。 / The closed-end funds discounts have been an interesting phenomenon for a long period. Some theories based on economic rationale try to solve the puzzle but fail to get consistent conclusions. Recently some theories based on behavioral finance, such as the investor sentiment hypothesis, have been proposed to solve this puzzle. This study examines the investor sentiment hypothesis based on various time-series tests and finds some interesting results. Briefly, our conclusions are as follows: 1. The discounts can vary widely between funds and seem to be persistent in our sample period. 2. The local market indices are cointegrated with the domestic closed-end funds discounts and the information is flowed from the market to the closed-end funds, which support the investor sentiment hypothesis. 3. The causality relationship between the foreign closed-end funds and the local indices is not obvious. Based on this, the market segmentation hypothesis seems to hold in our sample, which indicates that investing in the foreign funds provide investors with the benefit of diversification. For future researches, we suggest that more the foreign funds should be included in the sample and the classification of the degree of investor sentiment and the categories of funds can also be improved.

This thesis examines the output-variability relationship and causal relationships among the inflation, the output growth and their uncertainties for the Central and Eastern European region during the period of time that covers the economic crisis of 2008. We apply the bivariate GARCH(1,1) model with the constant conditional correlation covariance matrix to obtain conditional variances that proxy the two uncertainties and use Granger causality test to determine the causal effects among four variables. We come up with a number of interesting results. First, we did not find statistical evidence neither for the inflation-output variability relationship nor for the Phillips curve. Second, we uncovered support for the positive causal effect of the inflation on its uncertainty and negative causal effect for the reverse direction. Additionally, we also found some support for the indirect negative causal effect of the inflation on the output growth. These results support the policy of low and stable inflation in the countries. Finally, we showed that crisis has a significant impact on the results, changing the behaviour of conditional variances and causal effects among the variables. Powered by TCPDF (www.tcpdf.org)

This paper focuses on analysing and modelling inflation and its dynamics in Czech Republic applying a special kind of econometric models. Firstly economic theory of inflation is mentioned - fundamental terms, measuring methods of inflation, the way Czech national bank is monitoring the inflation and obviously a short summary of historical evolution of inflation in Czech economy. In the second part of this paper two econometric concepts of modelling time series are introduced - vector autoregression models (VAR models) and volatility models, concretely ARCH and GARCH models. In connection with the VAR models, Granger causality, impulse response functions, cointegration and error correction models are described. The empirical part includes application of selected models on real time series of chosen macroeconomic indicators. The estimation outputs are interpreted and forecasts are implemented. The quality of chosen econometric models for modelling inflation in Czech Republic is discussed.

Causal inference may help us to understand the underlying mechanisms and the risk factors of diseases. In Genetics, it is crucial to understand how the connectivity among variables is influenced by genetic and environmental factors. Family data have proven to be useful in elucidating genetic and environmental influences, however, few existing approaches are able of addressing structure learning of probabilistic graphical models (PGMs) and family data analysis jointly. We propose methodologies for learning, from observational Gaussian family data, the most likely PGM and its decomposition into genetic and environmental components. They were evaluated by a simulation study and applied to the Genetic Analysis Workshop 13 simulated data, which mimic the real Framingham Heart Study data, and to the metabolic syndrome phenotypes from the Baependi Heart Study. In neuroscience, one challenge consists in identifying interactions between functional brain networks (FBNs) - graphs. We propose a method to identify Granger causality among FBNs. We show the statistical power of the proposed method by simulations and its usefulness by two applications: the identification of Granger causality between the FBNs of two musicians playing a violin duo, and the identification of a differential connectivity from the right to the left brain hemispheres of autistic subjects. / Inferência causal pode nos ajudar a compreender melhor as relações de dependência direta entre variáveis e, assim, a identificar fatores de riscos de doenças. Em Genética, a análise de dados agrupados em famílias permite investigar influências genéticas e ambientais nas relações entre as variáveis. Neste trabalho, nós propomos métodos para aprender, a partir de dados Gaussianos agrupados em famílias, o mais provável modelo gráfico probabilístico (dirigido ou não dirigido) e também sua decomposição em dois componentes: genético e ambiental. Os métodos foram avaliados por simulações e aplicados tanto aos dados simulados do Genetic Analysis Workshop 13, que imitam características dos dados do Framingham Heart Study, como aos dados da síndrome metabólica do estudo Corações de Baependi. Em Neurociência, um desafio consiste em identificar interações entre redes funcionais cerebrais - grafos. Nós propomos um método que identifica causalidade de Granger entre grafos e, por meio de simulações, mostramos que o método tem alto poder estatístico. Além disso, mostramos sua utilidade por meio de duas aplicações: 1) identificação de causalidade de Granger entre as redes cerebrais de dois músicos enquanto tocam um dueto de violino e 2) identificação de conectividade diferencial do hemisfério cerebral direito para o esquerdo em indivíduos autistas.