A Conditional Role-Involved Purpose-Based Access Control Model

This paper presents a conditional role-involved purpose-based access control (CPAC) model, where users dynamically activate conditional roles in accordance with the context attributes. Based on conditional role, access permissions are assigned that represent what can be accessed for what purpose to roles under certain conditions. On the other hand, conditional purpose is applied along with allowed purpose and prohibited purpose in the model. It allows users using some data for certain purpose with conditions (for instance, Tony agrees that his income information can be used for marketing purposes by removing his name). The structure of a CPAC model is defined and investigated. Access purpose is verified in a dynamic behavior, based on user attributes, context attributes, and authorization policies. Intended purposes are dynamically associated with the requested data object during the access decision. An algorithm is developed to achieve the compliance computation between access purposes and intended purposes and is illustrated with role-based access control (RBAC). Access purpose authorization and authentication in the model are studied with the hierarchical purpose structure. The model separates authorization of access purpose from access decision that improves the flexibility of private data control.     

The role of customer loyalty as a brand extension purchase predictor

The paper explores the relationship between customer loyalty to the retail brand and the purchase of non-traditional products and services (NTPS) offered by grocery retailers with their private label (i.e. over-the-counter products, photo printing, mobile communication services and travel booking). Customer loyalty to the retail brand is measured through its behavioral and attitudinal components. A survey was conducted administering a questionnaire to 480 retail customers in two stores belonging to different retail grocers. A binary logistic regression was then applied using the buying of at least one NTPS as the dependent variable (1 = buy; 0 = no buy) and behavioral loyalty and attitudinal loyalty as independent variables. Results show that attitudinal loyalty plays a significant role as buying predictor, but this depends on the NTPS offered. Theoretical and managerial implications are derived.     

Real effects of private equity investments: Evidence from European buyouts

This study investigates the effects of buyout deals on the ex-post performance of target companies. The analysis is based on a sample of 241 private-to-private buyouts involving European companies between 1997 and 2004 and a control sample of non-buyouts selected through a propensity score matching methodology. The paper explores three different dimensions of firm performance: size, profitability and productivity. The results indicate a positive impact of buyouts on the growth of total assets and of employment in target firms in the short- and mid-term. An equivalent clear pattern cannot be identified for productivity, while we estimate a lower operating profitability for buyout companies with respect to the control group three years after a deal is made. When we restrict the analysis to the sub-sample of buyout companies, we find that generalist funds negatively and significantly impact the mean ex-post operating profitability of PE-backed firms, while turnaround specialists are positively associated with operating profitability. The evidence also highlights that target companies whose lead investor is located in the same country show relatively higher ex-post profitability performance.     

Media effects on sustainable food consumption. How newspaper coverage relates to supermarket expenditures

Information provision is often considered to have an important role to play in changing consumers' choices. However, there is still no consensus on the mechanisms by which information might influence specific consumer expenditures, especially in relation to environmentally friendly food products. This paper explores whether the public debate on sustainable consumption in UK broadsheets and tabloids relates to observed consumers' expenditures. It does so by relating the number of published articles on selected sustainability topics to consumers' food expenditure in a leading UK supermarket from May 2009 to May 2011, using regression analysis. We selected only regular supermarket's shoppers who frequently buy the Sunday editions of the analyzed newspapers. Results indicate very sparse and inconsistent correlations suggesting that the impact of information is only minimally effective. The number of newspaper articles relates mainly to expenditures on organic, wholegrain and low salt products, possibly indicating a preference for healthy food. No consistent effects are observed when media target a change in more general food categories (e.g. a reduction in food of animal origin), although we observed some influence on purchases of fish. Finally, results indicate some correlations with purchases of meat for the readers of the Telegraph. In order to contextualize some of the results, we applied content analysis to a subsample of published articles on organic food. The qualitative approach shows that the framing of the news is important: change is positively related to information proposed uncritically; and negatively to information contextualized as a highly structured debate.     

VALUATION OF BARRIER OPTIONS VIA A GENERAL SELF‐DUALITY

Classical put–call symmetry relates the price of puts and calls under a suitable dual market transform. One well‐known application is the semistatic hedging of path‐dependent barrier options with European options. This, however, in its classical form requires the price process to observe rather stringent and unrealistic symmetry properties. In this paper, we develop a general self‐duality theorem to develop valuation schemes for barrier options in stochastic volatility models with correlation.     

The asymptotic expansion of the regular discretization error of Itô integrals

We study an Edgeworth‐type refinement of the central limit theorem for the discretization error of Itô integrals. Toward this end, we introduce a new approach, based on the anticipating Itô formula. This alternative technique allows us to compute explicitly the terms of the corresponding expansion formula. Two applications to finance are given; the asymptotics of discrete hedging error under the Black–Scholes model and the difference between continuously and discretely monitored variance swap payoffs under stochastic volatility models.     

The short‐time behavior of VIX‐implied volatilities in a multifactor stochastic volatility framework

We consider a modeling setup where the volatility index (VIX) dynamics are explicitly computable as a smooth transformation of a purely diffusive, multidimensional Markov process. The framework is general enough to embed many popular stochastic volatility models. We develop closed‐form expansions and sharp error bounds for VIX futures, options, and implied volatilities. In particular, we derive exact asymptotic results for VIX‐implied volatilities, and their sensitivities, in the joint limit of short time‐to‐maturity and small log‐moneyness. The expansions obtained are explicit based on elementary functions and they neatly uncover how the VIX skew depends on the specific choice of the volatility and the vol‐of‐vol processes. Our results are based on perturbation techniques applied to the infinitesimal generator of the underlying process. This methodology has previously been adopted to derive approximations of equity (SPX) options. However, the generalizations needed to cover the case of VIX options are by no means straightforward as the dynamics of the underlying VIX futures are not explicitly known. To illustrate the accuracy of our technique, we provide numerical implementations for a selection of model specifications.     

Angel Financing and the Performance of High‐Tech Start‐Ups

In this paper, we investigate what drives the performance of high‐tech start‐ups receiving angel financing, while taking a closer look at the capabilities (i.e., experience) and investment behavior of business angels (BAs). We exploit a new data set (extracted from Crunchbase), which consists of 1,933 high‐tech start‐ups that received at least one financing round from a BA. The results indicate that the experience of BAs in early stage investments is positively associated with additional receipt of follow‐on rounds of financing and sequential capital injections from venture capitalists (VCs). Later‐stage experience is positively associated with the start‐up's success (i.e., probability to be listed or acquired), but reduces the need for new VCs to invest in the start‐up. Furthermore, we find consistent evidence that start‐ups that combine BA and VC financing experience higher levels of funding amounts, additional VC financing, and an improved likelihood of success. Finally, we find that the co‐localization of BA investors and start‐ups in the same area facilitates the attraction of VC financing.     

Factors that influence the consumption of food outside the home in Brazil

The food sector has taken on an unprecedented dynamism in recent years. The processing and distribution of food, although heavily influenced by tradition, have seen intensive innovations, leading to changes in the way individuals consume. One of these changes is the consistent growth of the habit of eating outside the home. Consuming food outside the home involves a number of practices such as eating at commercial establishments that specialize in food (restaurants, fast food restaurants and snack bars) and those that offer food as a part of their services (hotels, in‐flight meals), and non‐commercial alternatives such as the homes of family and friends. In order to describe the eating habits of consumers in the town of Lavras in Minas Gerais State, Brazil, especially when it comes to eating outside the home, a quantitative study was conducted, with 413 questionnaires being distributed by convenience sampling. Among the main results are: (a) a search for variety as a motivator for eating outside the home; (b) convenience as an important element on many occasions of consumption; (c) more intensive consumption and more favourable attitudes towards eating out on the part of younger people, people with higher incomes, no children and a higher degree of schooling; (d) importance of paying for food by the kilo. When compared with a study conducted in England, important similarities were identified in socio‐demographic influences, although the cultural factors are notable when it comes to dishes and the types of eating establishment. The growing habit of eating out has therefore become a worldwide phenomenon, but with cultural and regional differences that have led to different rhythms in terms of change and the way food is supplied. The recovery of embedded cultural habits, with increased value being given to slow food, traditional dishes and tradition itself, appears to co‐exist with a productivity model of food courts, pasteurization and accessible prices. The occasion for consumption, which may be understood as the dichotomies of ‘weekday versus weekend’ or ‘convenience versus leisure’, is an important element that influences consumer behaviours. The undertaking of a cross‐cultural comparative study can be seen as an important step in this field of research.     

Feeling capable and valued: A prosocial perspective on the link between empathy and social entrepreneurial intentions

Empathy is a key trait distinguishing social entrepreneurs from traditional entrepreneurs, and an important antecedent of social entrepreneurial (SE) intentions. Yet, little research explains the mechanisms through which empathy motivates SE intentions. We argue that studying the link between the prosocial trait of empathy and the prosocial outcome of SE intentions requires a prosocial lens that traditional entrepreneurial intent theories cannot offer. Building on prosocial motives research, we propose that empathy explains SE intentions through two complementary mechanisms: self-efficacy (an agentic mechanism), and social worth (a communal mechanism). We find support for our hypotheses in a study of 281 university students.