Magister Commercii - MCom / The following research paper is based on employment intensity, arguing the notion that an increase in economic growth alone does not necessary increase the rate of employment in South Africa. In fact, other additional macroeconomic factors determine changes in the rate of employment, along with economic growth. This research measured the employment numbers in each South African sector with reference to sector-specific gross value added, to determine the level of elasticity of employment in each sector. This was done by extracting quarterly data in-between the year 1995 to 2019. For each sector, a unit root test was estimated, an ARDL bound test for cointegration, an error correction model. A stability and diagnostic test were conducted to test the fluidity of each regression model. The coefficient of each sector modelled indicated no correlation between employment and economic growth. In “all sectors”, the results of GVA were not influential enough to implement positive change in the levels of employment, thus, leading to jobless growth.

This thesis is comprised of five papers that all relate to bootstrap methodology in analysis of non-stationary time series. The first paper starts with the fact that the Dickey-Fuller unit root test using asymptotic critical value has bad small sample performance. The small sample correction proposed by Johansen (2004) and bootstrap are two effective methods to improve the performance of the test. In this paper we compare these two methods as well as analyse the effect of bias-adjusting through a simulation study. We consider AR(1) and AR(2) models and both size and power properties are investigated. The second paper studies the asymptotic refinement of the bootstrap cointegration rank test. We expand the test statistic of a simplified VECM model and a Monte Carlo simulation was carried out to verify that the bootstrap test gives asymptotic refinement. The third paper focuses on the number of bootstrap replicates in bootstrap Dickey-Fuller unit root test. Through a simulation study, we find that a small number of bootstrap replicates are sufficient for a precise size, but, with too small number of replicates, we will lose power when the null hypothesis is not true. The fourth and last paper of the thesis concerns unit root test in panel setting focusing on the test proposed by Palm, Smeekes and Urbain (2011). In the fourth paper, we study the robustness of the PSU test with comparison with two representative tests from the second generation panel unit root tests. In the last paper, we generalise the PSU test to the model with deterministic terms. Two different methods are proposed to deal with the deterministic terms, and the asymptotic validity of the bootstrap procedure is theoretically checked. The small sample properties are studied by simulations and the paper is concluded by an empirical example. / <p>Ogiltigt ISBN: 978-91-554-9069-0</p>

Periodically correlated time series generally exist in several fields including hydrology, climatology, economics and finance, and are commonly modelled using periodic autoregressive (PAR) model. For a time series with stochastic periodic trend, for which a unit root is expected, a periodically integrated autoregressive PIAR model with periodic and/or seasonal unit root has been shown to be a satisfactory model. The existing theory used the multivariate methodology to study PIAR models. However, this theory is convoluted, majority of it only developed for quarterly time series and its generalisation to time series with larger number of periods is quite cumbersome. This thesis studies the existing theory and highlights its restrictions and flaws. It provides a coherent presentation of the steps for analysing PAR and PIAR models for different number of periods. It presents the different unit roots representations and compares the performance of different unit root tests available in literature. The restrictions of existing studies gave us the impetus to develop a unified theory that gives a clear understanding of the integration and unit roots in the periodic models. This theory is based on the spectral information of the multi-companion matrix of the periodic models. It is more general than the existing theory, since it can be applied to any number of periods whereas the existing methods are developed for quarterly time series. Using the multi-companion method, we specify and estimate the periodic models without the need to extract complicated restrictions on the model parameters corresponding to the unit roots, as required by NLS method. The multi-companion estimation method performed well and its performance is equivalent to the NLS estimation method that has been used in the literature. Analysing integrated multivariate models is a problematic issue in time series. The multi-companion theory provides a more general approach than the error correction method that is commonly used to analyse such time series. A modified state state representation for the seasonal periodically integrated autoregressive (SPIAR) model with periodic and seasonal unit roots is presented. Also an alternative state space representations from which the state space representations of PAR, PIAR and the seasonal periodic autoregressive (SPAR) models can be directly obtained is proposed. The seasons of the parameters in these representations have been clearly specified, which guarantees correct estimated parameters. Kalman filter have been used to estimate the parameters of these models and better estimation results are obtained when the initial values were estimated rather than when they were given.

This study examines the dynamic interaction between housing prices, stock prices and the repo rate in the Stockholm region by using the Johansen tests for cointegration. Several studies have been done on this topic, but the results are mixed across the world, and not many have been done in Scandinavia. This study contributes to the literature by examining eleven years of monthly data for the housing prices in the Stockholm region. We find evidence of a long-run relationship between housing prices, stock prices and the interest rate. There is a negative relationship between housing prices and the interest rate as well as between stock prices and the interest rate, but a positive relationship between housing prices and stock prices.  However, the results are somewhat sensitive to model specification and therefore further studies on the topic are encouraged.

This study tests for the market efficiency of the Nairobi Securities Exchange (NSE) after the year 2000 to determine the effect of technological advancements on market efficiency. Data that is used is the NSE 20 share index over the period 2001 to 2015; and the NSE All Share Index (NSE ASI) from its initiation during 2008 to 2015. We cannot accept the Efficient Market Hypothesis (EMH) for the NSE using the serial correlation test, the unit root tests and the runs test. However, we can accept the EMH for the more robust variance ratio test. Overall, the results of the market efficiency are mixed. The most significant finding is that the efficiency of the NSE has increased since the year 2000 which suggests that advancements in technology have contributed to the increase in the market efficiency of the NSE. / Business Management / M. Com. (Business Management)

Dynamic panel data models are widely used by econometricians to study over time the economics of, for example, people, firms, regions, or countries, by pooling information over the cross-section. Though much of the panel research concerns inference in stationary models, macroeconomic data such as GDP, prices, and interest rates are typically trending over time and require in one way or another a nonstationary analysis. In time series analysis it is well-established how autoregressive unit roots give rise to stochastic trends, implying that random shocks to a dynamic process are persistent rather than transitory. Because the implications of, say, government policy actions are fundamentally different if shocks to the economy are lasting than if they are temporary, there are now a vast number of univariate time series unit root tests available. Similarly, panel unit root tests have been designed to test for the presence of stochastic trends within a panel data set and to what degree they are shared by the panel individuals. Today, growing data certainly offer new possibilities for panel data analysis, but also pose new problems concerning double-indexed limit theory, unobserved heterogeneity, and cross-sectional dependencies. For example, economic shocks, such as technological innovations, are many times global and make national aggregates cross-country dependent and related in international business cycles. Imposing a strong cross-sectional dependence, panel unit root tests often assume that the unobserved panel errors follow a dynamic factor model. The errors will then contain one part which is shared by the panel individuals, a common component, and one part which is individual-specific, an idiosyncratic component. This is appealing from the perspective of economic theory, because unobserved heterogeneity may be driven by global common shocks, which are well captured by dynamic factor models. Yet, only a handful of tests have been derived to test for unit roots in the common and in the idiosyncratic components separately. More importantly, likelihood-based methods, which are commonly used in classical factor analysis, have been ruled out for large dynamic factor models due to the considerable number of parameters. This thesis consists of four papers where we consider the exact factor model, in which the idiosyncratic components are mutually independent, and so any cross-sectional dependence is through the common factors only. Within this framework we derive some likelihood-based tests for common and idiosyncratic unit roots. In doing so we address an important issue for dynamic factor models, because likelihood-based tests, such as the Wald test, the likelihood ratio test, and the Lagrange multiplier test, are well-known to be asymptotically most powerful against local alternatives. Our approach is specific-to-general, meaning that we start with restrictions on the parameter space that allow us to use explicit maximum likelihood estimators. We then proceed with relaxing some of the assumptions, and consider a more general framework requiring numerical maximum likelihood estimation. By simulation we compare size and power of our tests with some established panel unit root tests. The simulations suggest that the likelihood-based tests are locally powerful and in some cases more robust in terms of size. / Solving Macroeconomic Problems Using Non-Stationary Panel Data

nÃo hà / Considerando o atendimento à restriÃÃo orÃamentÃria intertemporal do governo, analisa-se a solvÃncia das administraÃÃes pÃblicas municipais no Cearà a partir da proposta de Hamilton e Flavin (1986) e dos avanÃos de Levin et. al. (2002) e Im, Pesaran, and Shin (2003). Na impossibilidade de se praticar um jogo de Ponzi, uma administraÃÃo à considerada solvente se o dÃficit pÃblico segue uma trajetÃria estacionÃria. Para o exercÃcio empÃrico, dois testes de raiz unitÃria em painel sÃo utilizados e o perÃodo de anÃlise compreende os anos 2002 a 2008. Constata-se que as administraÃÃes pÃblicas municipais no Cearà sÃo solventes, muito embora uma anÃlise para oito macrorregiÃes tenha indicado que em duas delas a polÃtica fiscal seja insustentÃvel. Finalmente, a condiÃÃo de insolvÃncia nÃo parece ser determinada pelo tamanho econÃmico, jà a solvÃncia parece estar associada à afinidade polÃtica entre as prefeituras e as esferas maiores de governo. / Considering that the intertemporal budget constraint of the government is fulfilled, this work examines the long-run solvency of the public accounts of the municipalities of Ceara following Hamilton and Flavin (1986), Levin et al. (2002) and Im, Pesaran, and Shin (2003). If an administration does not use a Ponzi game it is considered solvent if the budget deficit has a stationary path. As an empirical exercise, two unit root tests in panel are used and the period of analysis covers the years 2002 to 2008. It appears that the municipalities governiments in Ceara are solvents, although an analysis for eight macro-regions has indicated that in two of them the fiscal policy is unsustainable. Finally, the condition of insolvency does not seem to be determined by economy size, since the solvency appears to be associated with political affinity between the municipalities and the larger spheres of government.

[pt] Esse estudo tem como objetivo efetuar previsões não condicionadas de demanda de energia elétrica no Brasil para a classe industrial entre os meses de Janeiro e Dezembro de 2010. Para tanto, verificou-se a causalidade entre as variáveis em estudo, em seguida se as mesmas eram estacionárias ou processos integrados. Posteriormente procedeu-se ao teste de co-integração, cujo intuito era determinar se as séries apresentavam alguma tendência comum ao longo do tempo. As previsões foram estimadas através do Modelo de Correção de Erros na abordagem Clássica (VAR/VEC) e Bayesiana (BVAR/BVEC) e, ao fim, efetuou-se uma análise comparativa através da média dos erros. Os resultados obtidos mostraram que a metodologia Bayesiana se fez mais acurada do que a metodologia Clássica. / [en] This thesis describes two multivariate statistical based approaches to generate unconditional monthly forecasts for the brazilian industrial electricity demand covering the lead time spanning from Jan/2010 to Dec/2010. For that, it was first checked the causality among the series involved followed by stationarity tests. It was also carried out cointegration tests to check the existence of long range trend among the series. The two approaches adopted were, respectivelly, the Classical Error Correction Vector Model (VAR/VEC) and the Bayesian counterpart (BVAR/BVEC); both modelling simultaneously the series involved in the study as a vector of time series that follow a kind of vector autoregressive structure. The results obtained with both, were compared, and, a main conclusion of the thesis, the Bayesian model produced better results, in terms of accuracy, them the Classical counterpart.

This study examines which monetary aggregates, namely nominal M0, M1 and M2, can be used by the People’s Bank of China to conduct monetary policy. The model includes real M0, M1 and M2 as the dependent variable respectively and their determinants, such as real income, real inflation rate, and real rate of one-year saving deposit. Johansen (1988) and Johansen and Juselius’s (1990) procedures are used to estimate the long-run relationship between the monetary aggregates and their variables. Short-run model is applied to M0, M1 and M2 respectively to see whether the error term is negative to validate the significance of the long-run relationship using the Ordinary Least Square estimation.

Considering the impact of transaction costs on trade volumes and prices in Europe, in our thesis, we carried out an overview of the costs of crossing borders and an assessment of the degree of fragmentation of the product market in this world area. Throughout the analysis, we paid attention to the country and/ or industry dimension and at how country- and sector-specific patterns affect the European product market integration process. A special attention is also devoted to the model specifications and estimation techniques. Having discussed extensively the foundations of the gravity equation and the properties of the gravity model with the aim of empirical works in the first chapter of our dissertation, chapter two provides a first assessment of the extent of the integration in Europe by measuring the trade intensity via an augmented gravity equation. The study measures the impact of regional trade agreements (RTAs) on Members’ trade in the European zone and highlights that despite the ongoing enlargement process of its free trade area, the European zone displays rather weak RTAs impacts - in comparison with what one could expect -. The chapter also highlights a number of caveats and difficulties when one wants to accurately measure the extent of trade creation brought about the RTAs in Europe. In particular, the existence of zero observations (non observed commodity flows) between country pairs might have important drawbacks in the estimations. Since disaggregated trade data can be very insightful, chapter three implements such an analysis. Using a gravity-like equation as well, it provides a border effect estimations carried out in a multi-country and multi-sector context. Our findings reveal that remaining technical barriers to trade, market structure and degree of product differentiation play an important role in the explanation of border effects. Furthermore, our results succeed to derive a strongly negative impact of nominal exchange rate volatility on trade, whereas traditional gravity specifications fail to identify this clearly – when regional dummies are introduced-. Hence, chapter two and three provide an overview, via the trade channel, of the degree of integration of the product market in Europe: While European agreements (EAs) in terms of trade are effective, bilateral trade relationships face steady impediments. As expected, intra-EAs trade increases and exports from Member States to non Member States decline. The trade obstacles have many sources. In particular, volatility of the nominal exchange rate is found to have trade-reducing effects. Our results also underscore the interest of using sector disaggregated date since we find that the degree of product differentiation and the market structure enter in the explanation of border effects. Moreover, the various approaches to harmonize the remaining technical barriers to trade on sector desegregation basis were found to act in reducing on the European Union border effect. As for chapter four, it re-visits the issue of price convergence within the EMU. Specifically, we test whether the Law of One Price (LOOP) can be validated over the period 1984-2004. Our results fail to support the LOOP for a large majority of sectors and countries under examination. Furthermore, our findings reveal half-lives of deviation from the LOOP suggesting a price adjustment which is globally less slow that commonly estimated in the literature. Indeed, the EMU is anticipated to affect the behaviour of trading firms that should result in a faster cross-border transmission of price movements across Member States. When attempting to explain the factors at work in the LOOP failure, we highlight that beside the European convergence process, the arbitrage channel explain a non negligible part of the country mean reversion in terms of relative prices. Nevertheless, mixed evidence is found for the impact of cross- country and cross-sector variables.