Tau Be or not Tau Be? - A Perspective on Service Compatibility and Substitutability

One of the main open research issues in Service Oriented Computing is to propose automated techniques to analyse service interfaces. A first problem, called compatibility, aims at determining whether a set of services (two in this paper) can be composed together and interact with each other as expected. Another related problem is to check the substitutability of one service with another. These problems are especially difficult when behavioural descriptions (i.e., message calls and their ordering) are taken into account in service interfaces. Interfaces should capture as faithfully as possible the service behaviour to make their automated analysis possible while not exhibiting implementation details. In this position paper, we choose Labelled Transition Systems to specify the behavioural part of service interfaces. In particular, we show that internal behaviours (tau transitions) are necessary in these transition systems in order to detect subtle errors that may occur when composing a set of services together. We also show that tau transitions should be handled differently in the compatibility and substitutability problem: the former problem requires to check if the compatibility is preserved every time a tau transition is traversed in one interface, whereas the latter requires a precise analysis of tau branchings in order to make the substitution preserve the properties (e.g., a compatibility notion) which were ensured before replacement.Comment: In Proceedings WCSI 2010, arXiv:1010.233

Leadership in Multi-sided Markets

I analyze the role of leadership in multi-sided markets as online advertising. Search and display advertising are better characterized by (respectively) quantity and price competition. A platform that reached dominance in search may have an incentive to limit services to consumers to be aggressive with the advertisers, to exploit its scale in search to build barriers to entry, or to adopt click-weighted auctions to manipulate the pricing of sponsored links. On the other side, a dominant platform in display advertising may increase the rewards of content providers to increase prices on advertisers, or may adopt exclusive clauses to predate on other platforms.Multisided markets, Leadership, Dominance

Economic Growth, Technical Progress, and Social Capital: the Inverted U Hypothesis

We set up a theoretical framework to analyze the possible role of economic growth and technical progress in the erosion of social capital. Under certain parameters, the relationship between technical progress and social capital can take the shape of an inverted U curve. We show the circumstances allowing the economy to follow trajectories where the stock of social capital grows endogenously and unboundedly.Social capital; technological progress; economic growth, social interactions

Live Streaming Commerce: Uses and Gratifications Approach to Understanding Consumers’ Motivations

In this paper, we introduce live streaming commerce– e-commerce integrated with real-time social interaction via live streams. Using a uses and gratifications framework, we identified four motivations (enjoyment of interaction, substitutability of personal examination, need for community, and trend setting) related to live streaming commerce, and explored relationships between motivations and behavioral intentions in three different scenarios: general watching scenario, product search scenario, and internet celebrity scenario. Results showed that substitutability of personal examination was associated with the general watching scenario and product search scenario, while enjoyment of interaction was associated with the internet celebrity scenario. Trend setting was associated with all scenarios but need for community was insignificant with all scenarios. Design implications based on results are discussed for future live streaming commerce system development

UKERC Review of evidence for the rebound effect: Technical report 3: Elasticity of substitution studies

This Working Paper forms part of the TPA’s assessment of evidence for a rebound effect from improved energy efficiency. Technical Report 3 focuses upon empirical estimates of the elasticity of substitution between energy and capital. This parameter has been identified as a key determinant of the likely magnitude of the rebound effect in different sectors. The report clarifies the meaning and importance of this parameter, summarises and compares empirical estimates of this parameter, evaluates the reasons that have been proposed for the differing results, discusses whether a consensus has been reached to whether energy and capital can be considered as ‘substitutes’ or ‘complements’ and draws some implications for the rebound effect