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We investigate the causal relationships between volatility implied in Major Market Index (MMI) options and its component stocks' options from January, 1987 to October, 1989. We find that MMI implied volatility Granger causes component stock implied volatility for all twenty component stocks, which is consistent with the hypothesis that changes in volatility in index options markets leads volatility in underlying component (cash) markets. When we further analyze the sample by subperiod, we find that the causal relationships are insignificant in the period after the October 1987 crash, which is consistent with the hypothesis that exchange and regulatory actions taken after the crash weakened the influence of index options markets on cash markets. Trading strategies and programs involving stock index options and futures have been blamed for increasing volatility of the stock market. Indeed, trading in index futures and options markets has been blamed for much of the drop in stock prices in the crash of October 1987. After the crash, regulators took several actions to reduce the influence of futures and options market volatility on cash market volatility. If regulators' fears were legitimate and their efforts were successful, the volatility linkage between index options markets and their underlying cash markets should have been weakened. This paper provides two important contributions to our understanding of the volatility implications of index options markets. First, we examine the causality relationships between index and component stock implied volatility to assess whether or not changes in volatility in the index option market lead changes in volatility in the underlying component stock markets. Second, we test whether the causal relationships differ before and after the October 1987 crash to assess whether or not regulatory actions after the crash caused a change in these relationships. We measure volatility using implied standard deviations (ISDs) from options on the Major Market Index (MMI) and its component stocks. We form time series of ISDs for both the MMI and its component stocks, and then apply Granger causality tests to the series. For the full sample period of January 1987 to October 1989, we find that changes in index ISDs do Granger cause changes in component stock ISDs for all twenty component stocks, evidence consistent with the notion that volatility in index option market leads volatility in the component (cash) market. When we analyze the sample by subperiod, however, we find that the significant Granger causality holds only in the period before the October 1987 crash. Post‐crash subperiods show insignificant causality relationships, which suggests that efforts taken by exchange officials and regulators to reduce the influence of volatility in the index options and futures markets on cash market volatility were successful. The remainder of the paper is structured as follows. In Section I we discuss the potential for causal relationships between index option markets and their component markets and review related literature. Section II contains a discussion of our methodology and a description of our data. Section III contains a discussion of our results and Section IV concludes.

The purpose of this paper is to use an evaluation of a micro-place-based hot-spot policing implementation to highlight the potential issues raised by data quality standards in the recording and measurement of crime data and police officer movements.

The study focusses on an area of London (UK) which used a predictive algorithm to designate micro-place patrol zones for each police shift over a two-month period. Police officer movements are measured using GPS data from officer-worn radios. Descriptive statistics regarding the crime data commonly used to evaluate this type of implementation are presented, and simple analyses are presented to examine the effects of officer patrol duration (dosage) on crime in micro-place hot-spots.

The results suggest that patrols of 10-20 minutes in a given police shift have a significant impact on reducing crime; however, patrols of less than about 10 minutes and more than about 20 minutes are ineffective at deterring crime.

Due to the sparseness of officer GPS data, their paths have to be interpolated which could introduce error to the estimated patrol dosages. Similarly, errors and uncertainty in recorded crime data could have substantial impact on the designation of micro-place interventions and evaluations of their effectiveness.

This study is one of the first to use officer GPS data to estimate patrol dosage and places particular emphasis on the issue of data quality when evaluating micro-place interventions.

While there is a large volume of entrepreneurial social capital research, the philosophical assumptions have received limited attention. The purpose of this paper is to review and classify entrepreneurial social capital studies according to the following approaches – objectivist (positivist-realist, structuralist) and subjectivist (social constructionist). There is a neglect of structure and agency, and the authors encourage a critical realist approach that permits an understanding of observable network structure, constraint-order and human agency as a dynamic system.

The ontological and epistemological assumptions, and associated strengths and weaknesses of objectivist (positivist-realist, structuralist) and subjectivist (social constructionist) entrepreneurial social capital studies are discussed. The case for a more progressive critical realist approach is developed.

The authors demonstrate that objectivist (positivist-realist, structuralist) research with findings bereft of situated meaning and agency dominates. The emergence of subjectivist research – narratively examining different network situations from the perspective of those embedded in networks – is an emerging and competing approach. This dualism is unlikely to comprehensively understand the complex system-level properties of social capital. Future research should adopt critical realism and fuse: objective data to demonstrate the material aspects of network structures and what structural social capital exists in particular settings; and subjective data that enhances an understanding of situated meaning, agency and intention in a network.

This paper contributes a review of entrepreneurial social capital research and philosophical foundations. The development of a critical realist approach to understanding social capital gestation permits a system-level analysis of network structure influencing conduct, and agency.

It is clear that entrepreneurship has a major impact on the economy because of the innovation, competition, productivity, wealth generation, and job creation all developed through new ventures. However, researchers have been divided on what specific type of entrepreneurial venture is best for economic growth and job creation. This chapter examines the debate between researchers on whether or not a “gazelle” approach, focusing only on high growth ventures, or a “portfolio” approach, taking in account all the various types of ventures, is better for economic growth and job creation. The gazelle approach’s solution is for the government to only invest in those firms that are high growth. In contrast, the portfolio approach’s solution is to encourage all forms of entrepreneurship because the ventures are interdependent on each other in the entrepreneurial ecosystem and each venture no matter the size is serving some purpose to the economy. This chapter highlights the two sides of the issue but also argues that in order for a true entrepreneurial economy to exist then all various type of ventures need to be encouraged in order for competition to be greatest and for society to reap the highest benefits.

To use a behavioral measure of legitimacy to study how differences in negotiating style and status affect the legitimacy of persons in high-power network positions. Predictions include (1) that powerful network actors who negotiate using a pro-group style will maintain legitimacy better than will those who negotiate selfishly and (2) those higher in status will be granted more legitimacy both before and after exchange than powerful actors lower in status.

An experimental study in which participants were connected in networks to powerful partners who were portrayed as consistently high or low on several status characteristics. Both before and after exchange, participants evaluated partners on a number of dimensions and made decisions on whether to vote to join a coalition to take the partner's power away, a direct behavioral indicator of legitimacy.

High-power partners lost legitimacy over the course of exchange irrespective of whether they negotiated in pro-group or selfish ways, and irrespective of whether they were high or low in status. This effect was pronounced for partners who negotiated selfishly. Although partner status predicted legitimacy prior to exchange, legitimacy evaluations after exchange appeared entirely driven by the partner's negotiating style (how the power was used) and not by status.

The project introduces a new behavioral measure of legitimacy that correlated highly with self-report items and should be of value in future research. The study also indicates promising directions for future research that might disentangle effects of power and status on legitimacy, along with adjudicating among explanations for why this study did not find status effects on legitimacy.

Entrepreneurship-related research in management and organizational journals has experienced rapid growth, particularly in the last several years. The purpose of this study is to identify the researchers and universities that have had the greatest influence on entrepreneurship research since the turn of the century. Using a systematic and comprehensive study identification protocol, the authors delve into the individual and institutional actors contributing to scholarship in entrepreneurial studies for the period from 2000 to 2015. Examination of top-tier management and organizational journals revealed that a total of 371 entrepreneurship-related articles were published during this period by 618 authors from 303 different institutions. Rankings for the most prolific individuals as well as institutions, adjusted and unadjusted for journal quality, are presented. The article concludes with a discussion of the limitations and implications of the research undertaken here.

We offer a theoretical account of how two types of bricolage influence the entrepreneurial process. The first type involves social relationships or physical or functional assets, and thus pertains to an entrepreneurʼs external resources used in the instantiation of operations of a new venture. The second type pertains to an entrepreneurʼs internal resources‐experiences, credentials, knowledge, and certifications‐which the entrepreneur appropriates, assembles, modifies and deploys in the presentation of a narrative about the entrepreneurial process. We argue that both types of bricolage are essential to the success of a venturing attempt.