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This thesis is a collection of three essays in which the behaviour of unemployment is studied in different dynamic environments. Throughout, unemployment is understood to be involuntary, arising due to the uncoordinated nature of trade in the labour market as viewed from the perspective of the Diamond-Mortensen-Pissarides equilibrium matching model. It goes without saying that the fundamental motivation for pursuing this line of research is provided by the untold consequences, both human and economic, of otherwise capable people remaining involuntarily idle. An attempt, therefore, is made to contribute to the understanding of how various aspects of macroeconomic policy can influence unemployment outcomes. The approach maintained throughout is to combine general equilibrium modelling with simulation techniques in order to provide not only qualitative inferences but also quantitative descriptions of equilibrium dynamics. The dynamic environments considered cover both the business cycle (the first two chapters) and the life cycle (the third chapter). In the first chapter, Structural Tax Reform and the Cyclical Behaviour of the Labour Market, we build a real business cycle model with frictional unemployment and distortionary tax rates which are increasing in individual taxable labour income. The cyclical aspects of tax reform that are addressed in this chapter are distinct from the stationary state distributional issues that have garnered most of the attention in the existing literature on structural tax reform. Estimating the tax code parameters from federal income tax return data for the U.S., we find that a reduction in the progressivity of the tax system is associated with a significant increase in the volatility of hours per worker. The intuition is simply that the greater the extent to which marginal tax rates fluctuate in response to shocks, the smaller the incentive to adjust working hours. But in a frictional labour market in which it is costly for forms to issue vacancies, the behaviour of hours - i.e. intensive adjustment, or adjustment in the intensive margin - is a determining factor of job creation - i.e. extensive adjustment. We then explain how the dynamic behaviour of hours along the adjustment path to an aggregate productivity shock generates o¤setting incentives for job creation, with the result that tax reform has little impact on unemployment fluctuations. The welfare cost of the business cycle is also computed under different tax regimes. It is found that although business cycles are more costly under a flat tax, the overall welfare implications are quantitatively negligible regardless of the tax system. Having described the effects of the tax system on equilibrium dynamics when perturbed by a productivity disturbance, we then consider business cycle adjustment to an aggregate demand shock in the form of fiscal stimulus. In light of recent fiscal developments in the U.S. and Europe, the ability of expansionary fiscal policy to stimulate output has gained renewed interest in the business cycle literature. We contribute to the analysis by assessing whether the efficacy of government expenditure in reducing unemployment depends on the structure of the tax system. It is demonstrated that a less progressive tax policy increases the ability of expansionary fiscal policy to stimulate output due to a larger response in hours, but this comes at the cost of a smaller unemployment multiplier. Tax reform therefore causes a compositional shift in labour market adjustment in response to aggregate demand shocks, with relatively more adjustment occurring in the intensive margin and less adjustment in the extensive margin the flatter the tax schedule is. The reason why this compositional shift occurs for a demand shock but not a supply shock is that the adjustment path of hours is qualitatively dependent on the type of disturbance. In particular, we describe how equilibrium undershooting in hours occurs only in response to an aggregate productivity (supply) shock, whereas the negative wealth effects arising from increased government expenditure exert sustained upward pressure on hours along the entire adjustment path, thus providing a significant incentive for firms to substitute away from job creation. The second chapter, Monetary Policy and Job Creation in a New Keynesian Model, is motivated by the work of Cooley and Quadrini (1999) and Krause and Lubik (2007). These studies indicate that a typical monetary business cycle model with frictional unemployment and endogenous job destruction tends to encounter difficulty in generating a rise in job creation in response to expansionary monetary policy, rendering the model inconsistent with the downward sloping Beveridge curve that appears in the data and implying only a limited policy role for inflationary job creation. Matching frictions in the labour market congest the job creation process so that firms tend to skew adjustment to shocks towards the job destruction margin. In recognition of the assertion put forth but unpursued by Cooley and Quadrini (1999) that fluctuations in the size of the labour force may ease labour market congestion and therefore amplify cyclical job creation, in Chapter II we extend a New Keynesian model with unemployment to feature an endogenous labour market participation decision. However, a baseline model with a standard degree of risk aversion tends to exhibit countercyclical labour force participation, which is inconsistent with the data. In order to address this issue, we propose the notion of labour market participation as a social consideration, which we demonstrate to be capable of generating procyclical participation incentives. The basic idea is that agents will tend not to exit the labour force during booms in order to "keep up with the Joneses". We then find that plausible fluctuations in the size of the labour force do not exert a quantitatively significant effect on job creation. In light of this result, we search for alternative mechanisms which may overturn the conclusion that inflationary policy is incapable of incentivising job creation. The approach taken involves switching focus to the characteristics of aggregate demand dynamics along the adjustment path to a monetary shock. It is well known that standard New Keynesian models fail to deliver the gradual, hump-shaped adjustment path to monetary policy shocks that is observed in the data. We argue that if aggregate demand experiences a persistent increase in response to a monetary shock instead of peaking on impact, the incentive for firms to create jobs becomes amplified. The intuition is that, since the job creation decision is forward-looking due to the presence of matching frictions, aggregate demand must rise persistently even after the shock takes place so that firms anticipate a further increase in aggregate demand in order for the time consuming process of issuing a vacancy to be justified. To demonstrate this, it is shown that, by altering the dynamics of aggregate demand, time-inseparability in the utility function can significantly improve the ability of expansionary monetary policy to increase job creation, allowing the model to generate a downward sloping Beveridge curve conditional on monetary shocks. In the appendix to Chapter II, we lend further credence to this hypothesis by describing how the manner in which monetary policy it- self is specified may give rise to hump-shaped adjustment dynamics and, consequently, amplify inflationary job creation. Finally, in Chapter III on Equilibrium Matching and Age Discrimination Policy, we abstract from business cycle issues and concentrate instead on the life cycle. Federal legislation prohibiting the discrimination of workers on the basis of age has been in place in the United States since the 1967 Age Discrimination in Employment Act.

This thesis analyses how and why the recurrent costs of water services are shared between different actors in the rural local government areas in Mali which are supported by the international NGO WaterAid. This analysis of the financing arrangements for rural water services is used to critically assess theory, policy and practice in three areas: the community-based management approach to service delivery, the role of decentralised local governments in supporting community management, and the ability of external organisations to influence institutional change. Empirical evidence is presented for the period 2008-2011, drawing on research fieldwork undertaken in collaboration with WaterAid and its partners in 2010 and 2011, as the organisation introduced its own Sustainability Framework to help understand and address the challenges to delivering sustainable rural water services. The thesis argues that approaches to understanding local institutions for natural resource management based on ‘critical institutionalism' (Cleaver 2012), which emphasises the importance of improvisation and adaptation across different scales, should be placed within broader political economy analysis frameworks for assessing challenges in public services delivery from national to local levels. The use of such a framework shows how WaterAid and its partners adopt a ‘critical institutionalist' perspective at community levels to support users in developing ways of raising funds for water services which draw on both traditional practices and NGO influences. However at local government and national levels their approach is based on ideas of ‘best practice' rather than ‘best fit' (Booth 2012): although the costs of local government support to communities under the model promoted by WaterAid lie within international benchmarks, it is unclear over what timescale this approach could be scaled up in Mali without donor support. This demonstrates the limited ability of local governments to ensure the delivery of decentralised public services without additional external resources and support themselves.

Bridges with orthotropic steel decks have been built across the world over the past 60 years because they provide high strength and stiffness at a relatively low cost. However, a number of these bridges have sustained fatigue fractures. The investigation described in this thesis was carried out in order to identify cost-effective fatigue crack mitigation techniques by using the deck surfacing to reduce the stresses in the steel deck. Epoxy asphalt with an expanded metal mesh was investigated with small- and large-scale laboratory tests. Finite element analyses were also performed. The small scale tests conducted at different temperatures and loading frequencies showed that asphalt stiffness increased with decreasing temperature and faster loading. The expanded metal mesh in the epoxy asphalt layer noticeably increased asphalt stiffness. In the large scale tests and finite element analyses, critical loading positions to cause stress concentrations at the fatigue prone rib-to-deck welded connections were determined with different tyre configurations. The stress reduction due to the deck surfacing was estimated for the critical loading positions. The full scale test specimen was subjected to actual truck tyres. With the effectiveness of mitigation techniques for fatigue cracks on orthotropic steel bridge decks known, a probability-based fatigue lifetime evaluation methodology using Monte Carlo simulation was developed. The deck surfacing effects with seasonal and hourly temperature variations were considered. The fatigue lifetime extension using the epoxy asphalt was quantified. For a particular bridge, cost-effective maintenance scenarios were investigated. A simple calculation method for fatigue lifetime was introduced for engineers or bridge owners to assist understanding of decision support tool concepts.

The scope of this work is to generate quantifiable measures of sustainability elements that apply to manufactured products in terms of environmental, social and economic benefits. This thesis presents a comprehensive analysis for developing a methodology to compare the costs encountered by a vehicle over its entire life-cycle (Pre-manufacturing, Manufacturing, Use, and Post-use stages), considering two different material scenarios, aluminum versus steel, used in body-in-white (BIW) structures and exterior body panels. The potential benefits of using lighter materials in auto body applications are further evaluated through a Sustainability Scoring method. The proposed six major integral sustainable elements considered in this work are: products environmental impact, societal impact, functionality, resource utilization and economy, manufacturability and recyclability/remanufacturability. Each of these elements has corresponding sub-elements and influencing factors which are categorized as having equal importance to the product.

Abrasive Waterjet cutting (AWJ) presents many advantages over competing machining techniques, but several issues are related to the high volume of materials (and in particular of abrasive) used in the process. In this study, the environmental impact of the material flows in the abrasive waterjet industry has been analyzed adopting a life cycle perspective in order to individuate which phases place the largest burden on the environment. Moreover, three alternative abrasives (crushed rock, recycled glass and synthetic abrasive) and three disposal practices (in-site recycling, off-site recycling and recycling as construction material) have been also evaluated to estimate the benefits that can be achieved if these could be used in place of garnet abrasives and landfilling. The transportation of the abrasive resulted to be the phase that has the largest influence in every case and thus should be reduced as much as possible. For what concerns the alternative options, the usage of recycled glass and the in-site recycling of the abrasive were the two alternatives with the best environmental performances. However, crushed rock could be the best option for what concerns the global warming potential if carbon sequestration due to carbonation of silicate rocks is taken into account. Off-site recycling and recycling as construction material are good options only if the transportation to the recycling site can be reduced. Synthetic abrasive are instead found to have a much larger impact compared to every other alternative examined.

This study sheds light on the firm-lifecycle and the impact of leadership and how itdevelops negatively when the entrepreneurial firm becomes administrative andmanagerial. The ambivalent fact is that the firm, when growing in size, need to becomemore managerial, though without undermining the previously entrepreneurial mind-setthat pervade the organization. The term corporate entrepreneurship has emerged andcomprises that the firm can continue to be entrepreneurial in the managerial stage. Thatis to resume the firm’s work to keep innovative. The article seeks to find out how theleadership can be adapted for the firm to stay innovative through the managerial stage.

Aim of study: The purpose of this study is to investigate the current knowledge management status within the Academic Information Service at the University of Pretoria. Research method: A literature study was conducted to establish the nature and value of knowledge management for organizations. A questionnaire was used to obtain reliable information with regard to the current value and nature of knowledge management within the Academic Information Service at the University of Pretoria. Core findings: Within an academic library like the Academic Information Service at Pretoria, there exist a certain misconception that libraries are already doing knowledge management for years. The management of knowledge for clients, and providing knowledge and information to the client are seen as knowledge management. It was indicated that within the Academic Information Service there is not much attention given to the management of tacit knowledge within the organization. This shows that libraries aren’t doing knowledge management for years. They are doing explicit management of knowledge but not tacit management of organizational knowledge. Within this study it is stressed why this tacit knowledge is so important for an organization to exist and compete within these turbulent times we live in. The academic information service is not managing their tacit knowledge to the fullest potential and for benefit of the organization. There is no culture or incentives conducive to knowledge sharing within the library. The existing technology namely the intranet and portal aren’t re ally enablers for knowledge management. There exist a lot of barriers to knowledge management within the AIS that should be attended to. A knowledge management strategy is suggested with a lot of shifts in connection to the culture of the organization, incentives and information technology. / Thesis (MIT)--University of Pretoria, 2002.

There has been an increased awareness of the inter-dependence between man and the environment since the 1960’s. Environmental awareness has evolved from representing fairly radical views opposing all development, to a current emphasis on sustainable development between development and the environment. Life Cycle Assessment (LCA) is defined as the identification and quantification of the environmental impacts of a product, process or service during the entire life cycle being studied. The life cycle starts at the extraction of raw materials and the production of energy used to create the product through the use and final disposal of the product. LCA therefore considers the production, use and disposal of a product, which constitutes the life cycle of the product. LCA can be combined with methodologies that study other parameters such as costs in order to optimise the benefits from LCA. It is suggested that cost implications of processes to reduce environmental impacts should be included in a methodology used for a Platinum LCA. A comment that is consistently raised in the case studies is that the minerals industry regards LCA as an effective tool to determine the impacts of the industry, however extraction & beneficiation of minerals are often grouped together, with accurate data not being available, and databases either not available or not updated. The case studies indicated several benefits from the various LCA’s conducted. A Platinum LCA should clearly define and group the environmental impacts being studied into categories such as greenhouse gas emissions, global warming, acidification, and resource consumption. A Platinum LCA will be resource- and time intensive due to the large scale of the processes involved. It is suggested that a Platinum LCA firstly focuses on the production phase, i.e. cradle-to-gate, with potential future work done on the use and end-of-life stages. It is suggested that individual facility-based LCA’s for AMPLATS and other platinum producers are conducted in order to get a true reflection of the environmental burden of each company, and then selectively share technological improvements to reduce the environmental burden without disclosing sensitive information. The benefit of LCA in the case of platinum will be optimised if it can be used to make business decisions, together with consideration of financial and production benefits in addition to anticipated environmental benefits of alterations to processes. It is essential that LCA is seen as a business tool that will assist the company to make informed business decisions about process improvements, as well as new projects and design of new facilities. LCA on its own will not determine which product or process is the most cost effective or works best. The information developed in a LCA study should be used as one component of a more comprehensive decision making process assessing the trade-offs with cost and performance. The results from a LCA could be used to make informed decisions about optimisation between costs and reduced environmental impacts. / Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2011.

Aim of study: The purpose of this study is to investigate the current knowledge management status within the Academic Information Service at the University of Pretoria. Research method: A literature study was conducted to establish the nature and value of knowledge management for organizations. A questionnaire was used to obtain reliable information with regard to the current value and nature of knowledge management within the Academic Information Service at the University of Pretoria. Core findings: Within an academic library like the Academic Information Service at Pretoria, there exist a certain misconception that libraries are already doing knowledge management for years. The management of knowledge for clients, and providing knowledge and information to the client are seen as knowledge management. It was indicated that within the Academic Information Service there is not much attention given to the management of tacit knowledge within the organization. This shows that libraries aren’t doing knowledge management for years. They are doing explicit management of knowledge but not tacit management of organizational knowledge. Within this study it is stressed why this tacit knowledge is so important for an organization to exist and compete within these turbulent times we live in. The academic information service is not managing their tacit knowledge to the fullest potential and for benefit of the organization. There is no culture or incentives conducive to knowledge sharing within the library. The existing technology namely the intranet and portal aren’t re ally enablers for knowledge management. There exist a lot of barriers to knowledge management within the AIS that should be attended to. A knowledge management strategy is suggested with a lot of shifts in connection to the culture of the organization, incentives and information technology. / Thesis (MIT)--University of Pretoria, 2002.