Context-Sensitive Access Control Model for Government Services

During the past two decades, e-government information systems have become less paper-based and more computer-based. Those information systems usually take the form of workflow systems. Due to the large social impact of e-government systems, computer security plays a pivotal role in ensuring its efficiency and effectiveness. Access control is one of the key aspects of computer security. Current access control models do not take into account the context of the system and its environment. In this article, we argue that a formal context-sensitive access control model can improve the development of e-government workflow systems and present a particular context-sensitive access control model. The subject of the article is a specification of the context-sensitive access control model for business processes (COBAC). By using a context-sensitive access control, it is possible to define more sophisticated access control policies that cannot be implemented by existing access control models. The COBAC's context is modeled using Web Ontology Language (OWL) in order to provide formal representation of context, rich representation of diverse contextual information, semantic interoperability between various context-aware systems, and a high degree of inference making. The presented model is applicable in different e-government systems, and supports the definition of access control policies for both simple and complex business processes. The model's prototype is verified by a case study on a real e-government business process—the national petty offense trial proceedings.     

The determinants of service exports from Central and Eastern Europe

The transition economies of Central and Eastern Europe (CEE) have become important exporters of many types of services to Western Europe. We identify the sources of CEE’s advantages over competing exporters, such as India, China and Brazil, using disaggregated data on service exports and a novel estimation technique for the gravity equation. Our results indicate that the importance of geographical distance varies substantially across types of service exports. Geography is important for exports of construction services, but it has a negligible impact on computer‐related services. However, the relative quality of legal institutions influences trade across a broad range of service categories. The results demonstrate that aggregating services that are not homogeneous could conceal important differences in the effects of geographical distance and other variables on the pattern of service trade.     

Trade integration and within-plant productivity evolution in Chile

We analyze the impact of trade integration on plant TFP using Chilean plant-level data (1982–1999) and 3-digit bilateral trade flows. Our contribution is to disentangle the impact of export and import barriers, estimated as border effects within a multilateral context. A fall in export barriers is positively correlated with plant productivity in traded sectors. The reduction of import barriers, however, can only be associated to productivity improvements in export-oriented sectors. In import-competing sectors a robust positive correlation shows up between plant productivity and protection. We then test several channels linking trade integration and firm productivity.     

Investment opportunities in the source country and temporary migration

Abstract This paper examines how attractive investment opportunities available to temporary migrants at home affect their saving behaviour and the optimal duration of stay abroad. The model predicts an inverse U‐shaped relationship between migration duration and the expected rate of return on repatriated savings. A higher rate provides an incentive to go back earlier and consume less abroad, while it can also trigger emigration aimed at generating the savings required for investment after return. The paper illustrates how the behaviour of temporary migrants reflects the interaction between their preferences and the opportunities available in labour and capital markets of both countries.     

Britt,Steuart Henderson. Psychological Principles of Marketing and Consumer Behavior. Lexington,Mass.: Lexington Books, 1978

Abstract

Conventionally, an advertiser's spending on the creative component of an advertising campaign is small in relation to the media budget and is channeled exclusively to a single advertising agency. Gross challenged those conventions more than 20 years ago, using a mathematical model of advertising effectiveness. His model suggested spending more on the creative component and doing so in a competition among several independent sources. The model assumed a normal distribution of effectiveness of advertisements. Data on response to consumer product ads show that the distribution of effectiveness is not normal, but quite skewed. Using Monté Carlo simulations and Gross's framework, the authors find that the skewness strengthens the case for competition. Shifting a sizable percentage of a campaign budget away from media spending and into competitive generation of creative renderings apparently can be very profitable.     

The Compatibility of Advertising Regulation and the First Amendment

This article argues that advertising regulation and the First Amendment are not nearly so incompatible as has been popularly suggested. The reason lies in their common historical roots. Advertising regulation has its origins in the law of caveat emptor, a law of freedom of speech established from the same philosophical background as was the First Amendment. This relationship is described, and implications for present and future regulation are discussed.     

Economy as a Social System: Niklas Luhmann's Contribution and its Significance for Economics

Niklas Luhmann's (1927–1998) ambitious research project was aimed not only at describing society as a global social system, but it also analyzed various subsystems (including an economic one). The article assesses Luhmann's vision of the economy, summarized mainly in his Wirtschaft der Gesellschaft, wherein he addresses basic economic notions: the economic system, money, prices, rationality, and the market. I then interpret his ideas in the context of modern discussions in economics (intersubjective structures, complex systems, and evolutionary modeling). I also propose some heuristics implied by Luhmann's economic ontology, which are potentially interesting for methodological and theoretical strategies of modern economics.