396 research outputs found
Competition and quality in the notary profession
The 1999 Dutch Notary Act has initiated an ambitious deregulation process in the market for notary services in the Netherlands. We evaluate the impact of this liberalisation policy on (i) the level of competition in the profession and (ii) the quality of services. We compare the level of competition before and after the liberalisation using two different indicators, namely a relative-profit indicator and a variation of the Bresnahan-Reiss indicator. Using the relative profit indicator, we find that the level of competition has increased after 1999. We find, however, no significant difference between the level of competition in 1996 and in 2002. This is particularly clear when we measure competition taking the local market as the relevant market for notary services. The results on the national market are more mixed and there is some evidence that competition in 2002 is higher than in 1996. Using the Bresnahan-Reiss indicator, we find that entry does affect conduct in the notary market, but again that the level of competition in the local market for notary services in 2003 does not significantly differ from the 1995 level. We also examine whether competition affects the quality of notary services. We use both subjective and objective measures for quality of notary services. We find that subjective quality - the perceived level of service by clients - is, if anything, negatively affected by competition. Using objective quality, i.e. quality that is not observable to clients, we find that in 2003 competition leads to a deterioration of quality, as the quality of monopoly notaries outperforms the quality of oligopoly notaries. This was not the case in 1995. Confronting our empirical findings with qualitative insights, we present options for policy.
Model developments for in silico studies of the lumbar spine biomechanics
Premi extraordinari doctorat curs 2008-2009, àmbit Enginyeria IndustrialLa present tesi investiga l'ús de la modelització amb elements finits per a l'estudi de la biomecànica lumbar per a l'avaluació clínica. Els estudis bibliogràfics del capítol 1 mostren relacions funcionals clares entre les forces externes i les estructures i formes del teixit lumbar. Els estudis clínics demostraren que independentment del seu origen, el dolor lumbar pot veure's empitjorat per sobrecàrregues dels teixits. Les mesures experimentals són insuficients per descriure la distribució de càrrega entre els diferents teixits lumbars, és així que s'han utilitzat models d'elements finits. No obstant, la fiabilitat dels models a l'hora de predir les càrregues locals en els teixits no ha estat demostrada, essent aquest un dels objectes d'estudi.En el Capítol 2 s'elaborà un model bisegment de la columna lumbar. El model inicial es completà incloent el còrtex vertebral, una definició complerta de les juntes sinovials, les plaques terminals de cartílag i una descripció millorada de l'estructura de l'anell. Es van simular càrregues simplificades per als estudis in vitro per calcular les distribucions de tensions, deformacions i energia. El model bisegment és vàlid per interpretar les distribucions de càrrega funcionals a L3-L5 en el cas d'estructures conegudes de teixit, però el conjunt de la geometria L3-L5 necessitava ser millorat.Així al Capítol 3 es creà un model geomètric bisegment precís de L3-L5. El nou model incloïa les corregides: dimensions i formes, alçades de disc, localitzacions del nucli, formes posteriors de l'os, i distribució dels lligaments. Després de comparar a nivell biomecànic l'antiga geometria amb la nova, els resultats mostraren que els rols relatius dels teixits modelats depenen de la geometria. En general, les distribucions de càrrega predites eren més fisiològiques en el nou model. En canvi, ambdós models, reprodueixen rangs experimentals de moviment, així doncs la seva validació hauria de tenir en compte les transferències de càrrega locals.El Capítol 4 es centra en la variabilitat dels angles creuats del col·lagen de l'anell. Es crearen quatre models bisegment amb organitzacions d'anell fibrós basats en la bibliografia comparant-se sota diverses càrregues. A més es proposà un paràmetre d'estabilització de l'anell per analogia a un tub de parets gruixudes. La biomecànica del model depenia en gran mesura de l'organització de l'anell fibrós, però el paràmetre d'estabilització era soviet contradictori amb les tensions i forces predites. Així, s'assumí que la geometria de la columna i l'organització de l'anell fibrós estaven lligades. Les xarxes d'anell de col·lagen adaptades es poden determinar numèricament, però els models d'anell haurien d'estar bastats en relacions mecanobiològiques.Al Capítol 5 es presenta un model de disc artificial acoblat amb el model de L3-L5. Models bisegment amb i sense implant van ser comparats amb càrregues controlades per força o desplaçament, incloent o no l'aproximació del pes del cos. La rigidesa de la pròtesi alterava generalment les distribucions de càrrega i les rotacions controlades per desplaçament conduint a grans efectes adjacents. Incloent el pes del cos les condicions de contorn semblaven més fisòlogiques que sense. Malgrat la rigidesa del nou disc, aquest sembla més prometedor que altres dispositius comercials.En aquesta tesi s'han creat sis models nous elements finits de la columna lumbar osteoligamentosa. Les simulacions han mostrat que l'ús fiable dels models requereix d'una descripció precisa de les càrregues locals i respostes mecàniques de teixits. Les prediccions locals van estar limitades qualitativament degudes al desconeixement de les estructures de teixit tou, equacions constitutives i condicions de contorn. En canvi, els models poden ser emprats com a laboratoris in silico per superar aquestes limitacions. Basat en la informació numèrica i experimental, s'ha proposat un procediment jeràrquic per al desenvolupament qualitativament fiable de models elements finits de la columna lumbar.This PhD thesis investigated the use of finite element modelling to study lumbar spine biomechanics for clinical assessment. Bibliographic studies reported in the first Chapter showed clear functional relations between external forces and lumbar spine tissue structures and shapes. Clinical research revealed that independently of its origin, low back pain may be worsened by altered tissue mechanical environments. Experimental measurements alone cannot truly describe the load distributions between the different lumbar spine tissues. Thus, finite element models have been used in the past. But model reliability in predicting local tissue loadings is still not manifest and has been explored in this thesis as described in the following chapters.In Chapter 2, a L3-L5 lumbar spine bi-segment model was built. An initial model was completed to include the vertebral cortex, a full definition of the facet joints, the cartilage endplates, and an improved description of the annulus fibre-reinforced structure. Simplified load-cases used for in vitro studies were simulated to calculate stress and strain energy distributions. Predictions within the L3-L5 lumbar spine bi-segment model could be interpreted in terms of functional load distributions related to known tissue structures, but the overall L3-L5 bisegment model geometry needed further update.Thus, in Chapter 3, a geometrically accurate L3-L5 lumbar spine bi-segment model was created. The new model included corrected L3 and L5 body shapes and dimensions, corrected disc heights and nucleus placements, corrected posterior bone shapes, dimensions, and orientations, and corrected ligament distributions. The new and old geometries were biomechanically compared. Results showed that the relative roles of modelled tissues greatly depend on the geometry. Predicted load distributions were generally more physiological in the new model. However, new and old models could both reproduce experimental ranges of motion, meaning that their validation should take into account local load transfers.Chapter 4 focuses on the variability of the annulus collagen criss-cross angles. Four bi-segment models with literature-based annulus fibre organizations were created and compared under diverse loads. Moreover, an annulus stabilization parameter was proposed by analogy to a thick walled pipe. Model biomechanics greatly depended on the annulus fibre organization, but annulus stabilization parameter was often contradictory with the predicted stresses and strains. Spine geometry and annulus fibrous organization were hypothesized to be linked together. Adapted annulus collagen networks may be numerically determined, but annulus modelling should be based on mechano-biological relationships.In Chapter 5, a case-study of a novel artificial disc design coupled with the L3-L5 lumbar spine model is presented. Bi-segment models with and without implant were compared under load- or displacement-controlled rotations, with or without body-weight like load. Prosthesis stiffness generally altered the load distributions and displacement-controlled rotations led to strong adjacent level effects. Including body weight-like loads seemed to give more realistic results. Although the novel disc substitute is too stiff, it is more promising than other existing commercial devices.In this thesis, six new osteoligamentous lumbar spine bi-segment finite element models were created. Simulations showed that reliable use of lumbar spine finite element models requires precise descriptions of local tissue loading and response. Local predictions were qualitatively mainly limited by a lack of knowledge about soft tissue structural organisations, constitutive equations, and boundary conditions. However, models can be used as in silico laboratories to overcome such limitations. A hierarchical procedure for the development of qualitatively reliable lumbar spine finite element models was proposed based on available numerical and experimental inputs.Award-winningPostprint (published version
Do non-profits make a difference? Evaluating non-profit vis-Ã -vis for-profit organisations in social services
This CPB Document provides a framework for the evaluation of non-profit organisations. This framework addresses the question under which conditions, and, if so, in what way non-profits should be stimulated. Essentially, in order to answer these questions, three steps can be followed: (i) identifying potentially relevant market failures that non-profits may aim to diminish; (ii) linking market failures to observed performance indicators for profits and non-profits; and (iii) use these insights to derive policy implications: should non-profits be stimulated? We apply the proposed framework to three sectors that are commonly labelled as 'social services': the care sector, the childcare sector and welfare-to-work services. All these sectors are subject to substantial informational problems regarding the quality of services. When surveying the literature, we find non-profit organisations only to make a difference in some specific cases. So far, there is no strong evidence that can be used as an argument to stimulate non-profit organisations in mixed markets. Moreover, such (targeted) policies may discourage donated labour and private donations, thus rendering them largely ineffective.
The effects of competition on the quality of primary schools in the Netherlands
Do schools facing more competition in their neighbourhood perform better than schools facing less competition? As a measure of school quality, we look at the performance of pupils at the nationwide standard test (the so-called Cito test) in the final year of primary education. Since competition is likely to be endogenous to the quality of schools, we use the distance between the school and the town centre as an instrument for the level of competition faced by a school. The intuition is that schools located close to the town centre, which are easily accessible to a large number of parents, face more competition than schools located further away from the town centre. Using a large range of data on pupil, school and market characteristics, we find that school competition has a small positive significant effect on pupil achievement. An increase in competition by one standard deviation (comparable to 5 additional schools in the market) increases pupil achievement at the Cito test by five to ten percent of the mean standard deviation, so about less than one point. This result is robust to a large range of specifications.
The impact of market forces on the provision of childcare: Insights from the 2005 Childcare Act in the Netherlands
In January 2005, the Dutch government introduced the Childcare Act which replaced the former financing system which had elements of both supply- and demand-financing with a fully demand-financing system. Whereas previously public funds partly flowed to suppliers in the form of subsidies granted by local municipalities, they now flow exclusively to parents who are free to choose their childcare provider. This reform was intended to stimulate market forces in the market for childcare. This paper examines the impact of the introduction of market forces on the provision of childcare in the Netherlands.
Home green home; a case study of inducing energy-efficient innovations in the Dutch building sector
This document provides a case study of policies aiming to foster technological innovations for ‘green’ buildings in the Netherlands. The study aims to provide 1) a detailed overview of the policy framework over the last thirty years, and 2) a picture of the level of innovations related to energy efficiency in buildings in the Netherlands. �The analysis shows an intensification of environmental policy in the Dutch building sector in the mid-1990s, followed by a slight decline after 2001. A striking feature of environmental policy in this sector is the large number of policy programs implemented successively for short periods of time. This might affect the stability and continuity of the policy framework and be damaging for innovation. Faced with high levels of uncertainty about future policies, firms may prefer to postpone risky investments in innovative activities. Finally, governmental R&D support for green innovations in general remains very low in the Netherlands. Descriptive data on patenting activities show that Dutch firms file nowadays about 150 patents annually in the field of energy efficiency in buildings. The Netherlands have a clear comparative advantage in the field of energy-saving lighting technologies, mainly due to intensive patenting activities by Philips. High-efficiency boilers also represent a substantial share of Dutch innovation activities in this domain over the last decades. In many other fields (such as insulation, heat-pumps and co-generation, solar boilers, etc), however, Germany, Austria and Scandinavian countries rank much higher than the Netherlands.
Improving the Energy-Efficiency of Buildings: The Impact of Environmental Policy on Technological Innovation
This paper investigates the impact of alternative environmental policy instruments on technological innovations aiming to improve energy-efficiency in buildings. The empirical analysis focuses on three main types of policy instruments, namely regulatory energy standards in buildings codes, energy taxes as captured by energy prices and specific governmental energy R&D expenditures. Technological innovation is measured using patent counts for specific technologies related to energy-efficiency in buildings (e.g. insulation, high-efficiency boilers, energy-saving lightings). The estimates for seven European countries over the 1989-2004 period imply that a strengthening of 10% of the minimum insulation standards for walls would increase the likelihood to file additional patents by about 3%. In contrast, energy prices have no significant effect on the likelihood to patent. Governmental energy R&D support has a small positive significant effect on patenting activities.Innovation, Technological Change, Patents, Energy-Efficiency, Buildings, Environmental Policy
Mécanismes de Contrôle de la Réactivité d'un Réacteur Orgel de 250 MWe. EUR 4042. = Mechanisms for controlling the reactivity of an Orgel reactor of 250 MWe. EUR 4042.
Local and Global Interactions in an Evolutionary Resource Game
Conditions for the emergence of cooperation in a spatial common-pool resource game are studied. This combines in a unique way local and global interactions. A fixed number of harvesters are located on a spatial grid. Harvesters choose among three strategies: defection, cooperation, and enforcement. Individual payoffs are affected by both global factors, namely, aggregate harvest and resource stock level, and local factors, such as the imposition of sanctions on neighbors by enforcers. The evolution of strategies in the population is driven by social learning through imitation. Numerous types of equilibria exist in these settings. An important new finding is that clusters of cooperators and enforcers can survive among large groups of defectors. We discuss how the results contrast with the non-spatial, but otherwise similar, game of Sethi and Somanathan (1996).Common property, Cooperation, Evolutionary game theory, Global interactions, Local interactions, Social norms
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