過去許多學術文獻針對租稅優惠吸引投資之效果進行實證分析，但實證結論並不一致。我國自1950年即開始實施一連串的租稅獎勵政策，時至今日，租稅減免仍是我國政府推動重大經濟政策慣用的誘因手段。為探討了解臺灣實施租稅優惠措施對投資變化之影響，本研究針對我國自民國50年代後期以來涉及租稅減免之相關法令進行整理，另為了充分量化這些租稅優惠措施，則參考國外相關實證文獻作法，建構了兩項租稅誘因指標作為虛擬變數，來追蹤自民國61年以來我國不同階段之減免稅狀態，並作為虛擬變數納入後續實證模型分析。 本研究利用相關變數之時間序列資料來探討租稅優惠對我國外人直接投資與國內私人投資之互動變化關係。研究步驟有三，首先，針對個別變數進行單根檢定，藉以確認變數的屬性，了解時間序列資料是否為衡定後，再利用Johansen共整合檢定法來估計和檢定多個變數，確認各變數間是否存在共整合關係後，以誤差修正模型來說明各變數間關係與整個變數脫離均衡關係後之動態調整情形。 實證結果顯示，就長期趨勢而言，我國實施之租稅優惠措施對吸引外人直接投資呈現負向且顯著之不良影響，另長期而言，租稅優惠誘因對刺激我國國內投資之變化確有顯著且正面助益，但影響效果之幅度不大。因此，本研究建議政府與其提供效果不明確之租稅誘因，不如致力於針對國家自身不完善的基礎建設或不穩定的總體經濟環境進行改善。 / Tax incentives have been in existence in Taiwan since 1950, and they are still very much on the agenda of the government. There is no agreement about the efficacy of incentives. Indeed there have been doubts about whether incentives have any effect on the economy since the 1950s. This has made some economists wonder why incentives are so popular despite the fact that their effects are either slight or unknow. This study conducts an empirical investigation of the impact of tax incentives on investment in Taiwan. We constructed two indexs of tax incentives which track the different types of incentives embarked upon by the government, and these indexes are then included in both foreign direct investment and private investment equations. Our testing procedure involves three steps. The first step involves tasting for the properties of the variables by conducting unit root teste. The second step involves testing for the long-run relationship between the variables using Johansen cointegration tests. And the third step involves estimating the long-run parameters and associated loading factors. The empirical results shows a significant negative impact of tax incentives on FDI, and a significant positive impact of tax incentives on private investment but the impact is slight. We suggest that rather than focusing on tax incentives, the country should concentrate on removing the factors that discourage investors such as poor infrastructural and institutions or macroeconomic instability.

<p>The objective of this study is to empirically examine the export-led growth hypothesis in Mozambique using quarterly time series data over the period of 1987-2004, applying a co-integration analysis, Engle and Granger&rsquo / s (1987) Error Correction Model (ECM) and the Granger causality test. The paper explores the causal relationship between economic growth and othe explanatory variables, such as real exports, imports, labour force, gross capital formation, terms of trade, civil war and natural disasters (the last two as dummy variables).</p>

This dissertation contains three independent essays relating energy economics. The first essay investigates price asymmetry of diesel in South Korea by using the error correction model. Analyzing weekly market prices in the pass-through of crude oil, this model shows asymmetric price response does not exist at the upstream market but at the downstream market. Since time-variant residuals are found by the specified models for both weekly and daily retail prices at the downstream level, these models are implemented by a Generalized Autoregressive Conditional Heteroskedasticity (GARCH) process. The estimated results reveal that retail prices increase fast in the rise of crude oil prices but decrease slowly in the fall of those. Surprisingly, retail prices rarely respond to changes of crude oil prices for the first five days. Based on collusive behaviors of retailers, this price asymmetry in Korea diesel market is explained. The second essay aims to evaluate the new incentive system for biodiesel in South Korea, which keeps the blend mandate but abolishes tax credits for government revenues. To estimate changed welfare from the new policy, a multivariate stochastic simulation method is applied into time-series data for the last five years. From the simulation results, the new biodiesel policy will lead government revenues to increases with the abolishment of tax credit. However, increased prices of blended diesel will cause to decrease demands of both biodiesel and blended diesel, so consumer and producer surplus in the transport fuel market will decrease. In the third essay, the Regression - Seasonal Autoregressive Integrated Moving Average (REGSARIMA) model is employed to predict the impact of air temperature on daily peak load demand in Houston. Compared with ARIMA and Seasonal Model, a REGARIMA model provides the more accurate prediction for daily peak load demand for the short term. The estimated results reveal air temperature in the Houston areas causes an increase in electricity consumption for cooling but to save that for heating. Since the daily peak electricity consumption is significantly affected by hot air temperature, this study makes a conclusion that it is necessary to establish policies to reduce urban heat island phenomena in Houston.

Advances in genomics allow researchers to measure the complete set of transcripts in cells. These transcripts include messenger RNAs (which encode for proteins) and microRNAs, short RNAs that play an important regulatory role in cellular networks. While this data is a great resource for reconstructing the activity of networks in cells, it also presents several computational challenges. These challenges include the data collection stage which often results in incomplete and noisy measurement, developing methods to integrate several experiments within and across species, and designing methods that can use this data to map the interactions and networks that are activated in specific conditions. Novel and efficient algorithms are required to successfully address these challenges. In this thesis, we present probabilistic models to address the set of challenges associated with expression data. First, we present a novel probabilistic error correction method for RNA-Seq reads. RNA-Seq generates large and comprehensive datasets that have revolutionized our ability to accurately recover the set of transcripts in cells. However, sequencing reads inevitably contain errors, which affect all downstream analyses. To address these problems, we develop an efficient hidden Markov modelbased error correction method for RNA-Seq data . Second, for the analysis of expression data across species, we develop clustering and distance function learning methods for querying large expression databases. The methods use a Dirichlet Process Mixture Model with latent matchings and infer soft assignments between genes in two species to allow comparison and clustering across species. Third, we introduce new probabilistic models to integrate expression and interaction data in order to predict targets and networks regulated by microRNAs. Combined, the methods developed in this thesis provide a solution to the pipeline of expression analysis used by experimentalists when performing expression experiments.

The worldwide economic downturn and recession in the second half of 2008 were mainly the result of the crises that influenced the world‟s financial markets. After the financial crisis, the extended period of rapid credit growth that was driven by asset price increases, especially property prices, came to an end. This identified two problems central to the theme of this study. The first problem was illustrated through the recent crisis, which showed that problems in the financial sector have a potentially destabilising effect on the economy, to such an extent that they also affect the real economy. The second problem highlighted by the recent financial crisis pertains to the current macroeconomic framework, which indicates policy failure to detect and deal with financial sector instabilities. The objective of this study was to develop a framework in which the influence that rapidly growing credit and asset prices have on financial stability could be determined. Two distinct empirical models were estimated in order to reach the main objective of this study. The first model established the influence that asset prices and credit growth have on the real economy. It concluded that a long-run relationship exists between inflation, real GDP, credit extended to the private sector, house prices and share prices. A bi-directional relationship was found between house and share price, which indicates the interdependence of asset prices in SA. The transmission channels assume that credit is influenced by interest rates, but the results also found that interest rates are largely influenced by credit. The second model determined the influence of asset prices and credit on financial stability. A significant long-run relationship was found between financial stability, share and house prices, and between share prices, credit and financial stability. It was found that credit and share prices can be used to signal financial instability, and share prices can help to determine future credit extended to the private sector. In addition, the empirical analysis indicated that a credit market squeeze will be experienced after a decrease in financial stability. Lastly, credit extended will increase as a result of shock to house and share prices and financial stability will decrease when there is a shock to share and house prices. / MCom (Economics), North-West University, Potchefstroom Campus, 2013

The worldwide economic downturn and recession in the second half of 2008 were mainly the result of the crises that influenced the world‟s financial markets. After the financial crisis, the extended period of rapid credit growth that was driven by asset price increases, especially property prices, came to an end. This identified two problems central to the theme of this study. The first problem was illustrated through the recent crisis, which showed that problems in the financial sector have a potentially destabilising effect on the economy, to such an extent that they also affect the real economy. The second problem highlighted by the recent financial crisis pertains to the current macroeconomic framework, which indicates policy failure to detect and deal with financial sector instabilities. The objective of this study was to develop a framework in which the influence that rapidly growing credit and asset prices have on financial stability could be determined. Two distinct empirical models were estimated in order to reach the main objective of this study. The first model established the influence that asset prices and credit growth have on the real economy. It concluded that a long-run relationship exists between inflation, real GDP, credit extended to the private sector, house prices and share prices. A bi-directional relationship was found between house and share price, which indicates the interdependence of asset prices in SA. The transmission channels assume that credit is influenced by interest rates, but the results also found that interest rates are largely influenced by credit. The second model determined the influence of asset prices and credit on financial stability. A significant long-run relationship was found between financial stability, share and house prices, and between share prices, credit and financial stability. It was found that credit and share prices can be used to signal financial instability, and share prices can help to determine future credit extended to the private sector. In addition, the empirical analysis indicated that a credit market squeeze will be experienced after a decrease in financial stability. Lastly, credit extended will increase as a result of shock to house and share prices and financial stability will decrease when there is a shock to share and house prices. / MCom (Economics), North-West University, Potchefstroom Campus, 2013

Multimedia services and applications became the driving force in the development and widespread deployment of wireless broadband access technologies and high speed local area networks. Mobile phone service providers are offering wide range of multimedia applications over high speed wireless data networks. People can watch live TV, stream on-demand video clips and place videotelephony calls using multimedia capable mobile devices. Mobile devices will soon support capturing and displaying high definition video. Similar evolution is also occurring in the local area domain. The video receiver or storage devices were conventionally connected to display devices using cables. By using wireless local area networking (WLAN) technologies, convenient and cable-free connectivity can be achieved. Media over wireless home networks prevents the cable mess and provides mobility to portable TVs. However, there still exit challenges for improving the quality-of-service (QoS) of multimedia applications. Conventional service architectures, network structures and protocols lack to provide a robust distribution medium since most of them are not designed considering the high data rate and real-time transmission requirements of digital video. In this thesis the challenges of wireless video streaming are addressed in two main categories. Streaming protocol level issues constitute the first category. We will refer to the collection of network protocols that enable transmitting digital compressed video from a source to a receiver as the streaming protocol. The objective of streaming protocol solutions is the high quality video transfer between two networked devices. Novel application-layer video bit-rate adaptation methods are designed for handling short- and long-term bandwidth variations of the wireless local area network (WLAN) links. Both transrating and scalable video coding techniques are used to generate video bit-rate flexibility. Another contribution of this thesis study is an error control method that dynamically adjusts the forward error correction (FEC) rate based on channel bit-error rate (BER) estimation and video coding structure. The second category is the streaming service level issues, which generally surface in large scale systems. Service system solutions target to achieve system scalability and provide low cost / high quality service to consumers. Peer-to-peer assisted video streaming technologies are developed to reduce the load of video servers. Novel video file segment caching strategies are proposed for more efficient peer-to-peer collaboration.

Optimising the throughput performance for wireless networks is one of the challenging tasks in the objectives of communication engineering, since wireless channels are prone to errors due to path losses, random noise, and fading phenomena. The transmission errors will be worse in a multihop scenario due to its accumulative effects. Network Coding (NC) is an elegant technique to improve the throughput performance of a communication network. There is the fact that the bit error rates over one modulation symbol of 16- and higher order- Quadrature Amplitude Modulation (QAM) scheme follow a certain pattern. The Scattered Random Network Coding (SRNC) system was proposed in the literature to exploit the error pattern of 16-QAM by using bit-scattering to improve the throughput of multihop network to which is being applied the Random Linear Network Coding (RLNC). This thesis aims to improve further the SRNC system by using Forward Error Correction (FEC) code; the proposed system is called Joint RLNC and FEC with interleaving. The first proposed system (System-I) uses Convolutional Code (CC) FEC. The performances analysis of System-I with various CC rates of 1/2, 1/3, 1/4, 1/6, and 1/8 was carried out using the developed simulation tools in MATLAB and compared to two benchmark systems: SRNC system (System-II) and RLNC system (System- III). The second proposed system (System-IV) uses Reed-Solomon (RS) FEC code. Performance evaluation of System IV was carried out and compared to three systems; System-I with 1/2 CC rate, System-II, and System-III. All simulations were carried out over three possible channel environments: 1) AWGN channel, 2) a Rayleigh fading channel, and 3) a Rician fading channel, where both fading channels are in series with the AWGN channel. The simulation results show that the proposed system improves the SRNC system. How much improvement gain can be achieved depends on the FEC type used and the channel environment.

This study empirically investigates the key macroeconomic determinants of economic growth in three Southern African Development Community countries, namely: Malawi, Zambia, and South Africa, using annual data for the period 1970-2013. The study uses the recently developed Autoregressive Distributed Lag bounds-testing approach to co-integration and error correction model. In Malawi, the study finds that investment, human capital development, and international trade are positively associated, while inflation is negatively associated with economic growth in the short run. In the long run, the results reveal that investment, human capital development, and international trade are positively and significantly associated, while population growth and inflation are negatively and significantly associated with economic growth. In Zambia, the short-run results reveal that investment and human capital development are positively and significantly associated, while government consumption, international trade, and foreign aid are negatively and significantly associated with economic growth. The long-run results reveal that investment and human capital development are positively and significantly associated, while foreign aid is negatively and significantly associated with economic growth. In South Africa, the study results show that in the short run, investment is positively and significantly associated, while population growth and government consumption are negatively and significantly associated with economic growth. In the long run, the results reveal that economic growth is positively and significantly associated with investment, human capital development, and international trade, but negatively and significantly associated with population growth, government consumption, and inflation. These results all have significant policy implications. It is recommended that Malawian authorities should focus on strategies that attract investment: in addition there is a need to improve the quality of education, encourage export diversification, reduce population growth, and ensure inflation stability. Similarly Zambian authorities should focus on creation of incentives that attract investment, provision of quality education: moreover they need to improve government effectiveness, encourage international trade and ensure the effectiveness of development aid. South African authorities are recommended to focus on policies that attract investments, the provision of quality education, and trade liberalisation: concomitantly there is also a need to reduce population growth, government consumption and inflation. / Economics / Ph.D. (Economics)

This study provides evidence of the relationship between bank-granted credit and business cycles in South Africa. The study is conducted in three phases, namely qualitative research (Phase I), quantitative research (Phase II) and econometric analysis (Phase III). A sequential (connected data) mixed methodology (Phase I and II) is used to collect and analyze primary data from market participants. The qualitative research (Phase I) involves structured interviews with influential or well informed people on the subject matter. Phase I of the study is used to understand the key determinants of bank credit in South Africa and to appreciate how each of the credit aggregates behaves during alternate business cycles. Qualitative survey results suggest key determinants of commercial bank credit in South Africa as economic growth, collateral value, bank competition, money supply, deposit liabilities, capital requirements, bank lending rates and inflation. The qualitative results are used to formulate questions of the structured survey questionnaire (Quantitative research- Phase II). The ANOVA and Pearman’s product correlation analysis techniques are used to assess relationship between variables. The quantitative results show that there is direct and positive relationship between bank lending behavior and credit aggregates namely economic growth, collateral value, bank competition and money supply. On the other hand, the results show that there is a negative relationship between credit growth and bank capital and lending rates. Overall, the quantitative findings show that bank lending in South Africa is procyclical. The survey results indicate that the case for demand-following hypothesis is stronger than supply-leading hypothesis in South Africa. The econometric methodology is used to augment results of the survey study. Phase III of the study re-examines econometric relationship between bank lending and business cycles. The study employs cointegration and vector error correction model (VECM) techniques in order to test for existence of long-run relationship between the selected variables. Granger causality test technique is applied to the variables of interest to test for direction of causation between variables. The study uses quarterly data for the period of 1980:Q1 to 2013:Q4. Business cycles are determined and measured by Gross Domestic Product at market prices while bank-granted credit is proxied by credit extension to the private sector. The econometric test results show that there is a significant long-run relationship between economic growth and bank credit extension. The Granger causality test provides evidence of unidirectional causal relationship with direction from economic growth to credit extension for South Africa. The study results indicate that the case for demand-following hypothesis is stronger than supply-leading hypothesis in South Africa. Economic growth spurs credit market development in South Africa. Overall, the results show that there is a stable long-run relationship between macroeconomic business cycles and real credit growth in South Africa. The results show that economic growth significantly causes and stimulates bank credit. The study, therefore, recommends that South Africa needs to give policy priority to promotion and development of the real sector of the economy to propel and accelerate credit extension. Economic growth is considered as the significant policy variable to stimulate credit extension. The findings therefore hold important implications for both theory and policy. / Business Management / D.B.L.