Shadow economy and entrepreneurial entry

We analyze theoretically and empirically the impact of the shadow economy on entrepreneurial entry, utilising 1998-2005 individual-level Global Entrepreneurship Monitor data merged with macro level variables. A simple correlation coefficient suggests a positive linear link between the size of the shadow economy and entrepreneurial entry. However, this masks more complex relationships. With appropriate controls and instrumenting for potential endogeneity where required, the impact of the shadow economy on entry is found to be negative, based on a linear specification. Moreover, there is also evidence of nonlinearity: entrepreneurial entry is least likely when the shadow economy is of medium size. We attribute the negative effects of shadow economy on entry to perceived strong competition faced by new entrants when the shadow economy is widespread. At the individual level, an extensive shadow economy has a more negative impact on respondents who are risk averse. In addition, in the economies where property rights are strong, the negative impact of the shadow economy is weaker.

Shadow economy and entrepreneurial entry

The impact of the shadow economy on entrepreneurial entry across countries is analyzed utilising 1998-2005 individual-level Global Entrepreneurship Monitor data and national macro-economic variables. A simple correlation coefficient suggests a positive relationship between the size of the shadow economy and the likelihood of entrepreneurial entry. However, this masks more complex relationships, if, as argued, the shadow economy is an embedded social phenomenon. With appropriate controls and instrumenting for potential endogeneity, the impact of the shadow economy on entry in a linear specification is found to be negative. Further, there is evidence of a U-shaped relationship: entrepreneurial entry is least likely when the shadow economy amounts to about a quarter of gross domestic product (GDP). At the individual level, an extensive shadow economy has a more negative impact on respondents who are risk averse. In addition, in the economies where property rights are stronger, the negative impact of the shadow economy is weaker. © 2012 Blackwell Publishing Ltd.

Assessing interactions of linear and nonlinear neuronal sources using MEG beamformers:a proof of concept

Objective: This study aimed to explore methods of assessing interactions between neuronal sources using MEG beamformers. However, beamformer methodology is based on the assumption of no linear long-term source interdependencies [VanVeen BD, vanDrongelen W, Yuchtman M, Suzuki A. Localization of brain electrical activity via linearly constrained minimum variance spatial filtering. IEEE Trans Biomed Eng 1997;44:867-80; Robinson SE, Vrba J. Functional neuroimaging by synthetic aperture magnetometry (SAM). In: Recent advances in Biomagnetism. Sendai: Tohoku University Press; 1999. p. 302-5]. Although such long-term correlations are not efficient and should not be anticipated in a healthy brain [Friston KJ. The labile brain. I. Neuronal transients and nonlinear coupling. Philos Trans R Soc Lond B Biol Sci 2000;355:215-36], transient correlations seem to underlie functional cortical coordination [Singer W. Neuronal synchrony: a versatile code for the definition of relations? Neuron 1999;49-65; Rodriguez E, George N, Lachaux J, Martinerie J, Renault B, Varela F. Perception's shadow: long-distance synchronization of human brain activity. Nature 1999;397:430-3; Bressler SL, Kelso J. Cortical coordination dynamics and cognition. Trends Cogn Sci 2001;5:26-36]. Methods: Two periodic sources were simulated and the effects of transient source correlation on the spatial and temporal performance of the MEG beamformer were examined. Subsequently, the interdependencies of the reconstructed sources were investigated using coherence and phase synchronization analysis based on Mutual Information. Finally, two interacting nonlinear systems served as neuronal sources and their phase interdependencies were studied under realistic measurement conditions. Results: Both the spatial and the temporal beamformer source reconstructions were accurate as long as the transient source correlation did not exceed 30-40 percent of the duration of beamformer analysis. In addition, the interdependencies of periodic sources were preserved by the beamformer and phase synchronization of interacting nonlinear sources could be detected. Conclusions: MEG beamformer methods in conjunction with analysis of source interdependencies could provide accurate spatial and temporal descriptions of interactions between linear and nonlinear neuronal sources. Significance: The proposed methods can be used for the study of interactions between neuronal sources. © 2005 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Satellite laser ranging and the ETALON Geodetic satellites

The technique of Satellite Laser Ranging is today a mature, important tool with applications in many area of geodynamics, geodesy and satellite dynamics. A global network of some 40 stations regularly obtains range observations with sub-cm precision to more than twelve orbiting spacecraft. At such levels of precision it is important to minimise potential sources of range bias in the observations, and part of the thesis is a study of subtle effects caused by the extended nature of the arrays of retro-reflectors on the satellites. We develop models that give a precise correction of the range measurements to the centres of mass of the geodetic satellites Lageos and Etalon, appropriate to a variety of different ranging systems, and use the Etalon values, which were not determined during pre-launch tests, in an extended orbital analysis. We have fitted continuous 2.5 year orbits to range observations of the Etalons from the global network of stations, and analysed the results by mapping the range residuals from these orbits into equivalent corrections to orbital elements over short time intervals. From these residuals we have detected and studied large un-modelled along-track accelerations associated with periods during which the satellites are undergoing eclipse by the Earth's shadow. We also find that the eccentricity residuals are significantly different for the two satellites, with Etalon-2 undergoing a year-long eccentricity anomaly similar in character to that experienced at intervals by Lageos-1. The nodal residuals show that the satellites define a very stable reference frame for Earth rotation determination, with very little drift-off during the 2.5 year period. We show that an analysis of more than about eight years of tracking data would be required to derive a significant value for 2. The reference frame defined by the station coordinates derived from the analyses shows very good agreement with that of ITRF93.

The effects of solar radiation pressure on the motion of an artificial satellite

This thesis documents an investigation of the effect of solar radiation pressure on the motion of an artificial satellite. Consideration is given to the methods required for the inclusion of the discontinuous effect of the Earth's shadow. The analysis resulting from the description of a deformed diffusely reflecting balloon satellite and an algorithm describing the effects of Earth reflected solar radiation pressure are developed, culminating in the application of the derived theory to the orbital data of the balloon satellite, Explorer 19.

The food superstore revolution:changing times, changing research agendas in the UK

This article considers the changing scope of research into UK food superstores over some three decades. Rather than catalogue changing market shares by format, we seek instead to show how such change links to national policy agendas. Academic research has evolved to address the growing complexities of the social, technological, economic and political impacts of the superstore format. We exemplify this by tracing the progression of retail change in Portsmouth, Hampshire, over 30 years. We discover that academic research can conflict with the preconceptions of some public policy makers. The position is exacerbated by a progressive decline in public information – and a commensurate rise in factual data held by commercial data companies – that leaves policy makers with a choice of which data to believe. This problem casts a shadow over the objectivity of macro-policy as currently formulated. Concerns currently arise because the UK Competition Commission (2006–2009 but ongoing) starts each inquiry afresh with a search for recent data. Furthermore, it has recently called for changes to retail planning – the very arena in which UK superstore research commenced.

Europeanization from below:the formation of gender equality policies in the Western Balkans

The article argues that, compared with the other countries in the Western Balkans, the Europeanization of gender equality policies in Bosnia and Herzegovina represents an interesting case of "Europeanization from below". It was not the EU, which called for the introduction of gender equality policies in the Stabilization and Association Process, but domestic policy entrepreneurs, who constructed a "shadow of membership conditionality". They framed their requests as element of the accession process tapping into the aspiration of policy-makers to joining the EU. The case illustrates that Europeanization matters in the Western Balkans, not only in terms of a direct influence of the EU but also because it provides opportunities for domestic policy entrepreneurs to further European objectives themselves.

Online two-section PV array fault diagnosis with optimized voltage sensor locations

Photovoltaic (PV) stations have been widely built in the world to utilize solar energy directly. In order to reduce the capital and operational costs, early fault diagnosis is playing an increasingly important role by enabling the long effective operation of PV arrays. This paper analyzes the terminal characteristics of faulty PV strings and arrays, and it develops a PV array fault diagnosis technique. The terminal current-voltage curve of a faulty PV array is divided into two sections, i.e., high-voltage and low-voltage fault diagnosis sections. The corresponding working points of healthy string modules and of healthy and faulty modules in an unhealthy string are then analyzed for each section. By probing into different working points, a faulty PV module can be located. The fault information is of critical importance for the maximum power point tracking and the array dynamical reconfiguration. Furthermore, the string current sensors can be eliminated, and the number of voltage sensors can be reduced by optimizing voltage sensor locations. Typical fault scenarios including monostring, multistring, and a partial shadow for a 1.6-kW 3 $times$ 3 PV array are presented and experimentally tested to confirm the effectiveness of the proposed fault diagnosis method.