|
on Information and Communication Technologies |
| By: | Kevin Mellet |
| Abstract: | Two factors play a decisive role in the structuring of Internet based markets for infomediation (informational intermediation) : network externalities and information processing. First, these are examined separately. The two-sided markets literature focuses on the impact of network externalities in a context of competition among 2-sided platforms. It explains the level of concentrationfragmentation of those markets, and explores its welfare implications. We shall call this model the "horizontal" model of structuring. Symetrically, a "vertical" process of division of labour among the infomediaries' value chain is observed. It results of the complexification of intermediation in a context of strong quality uncertainty and high codification investments. Intermediaries specialize and develop cooperative relationships with each others. Secondly, the paper examines the implications of the simultaneous co-existence of H and D dynamics on the structuring of the market for infomediation. This co-existence generates frictions. Two levels of frictions are distinguished : i) market governance (standards and certifications) ; ii) commercial interactions (the so-called 'coopetition'). Empirical illustrations are taken from the analysis of Internet based labour market intermediaries. |
| Keywords: | Two-sided markets; competition; vertical specialization; regulation; coopetition; labour market intermediaries. |
| Date: | 2007 |
| URL: | http://d.repec.org/n?u=RePEc:drm:wpaper:2007-13&r=ict |
| By: | James G. MacKinnon (Queen's University) |
| Abstract: | This paper surveys bootstrap and Monte Carlo methods for testing hypotheses in econometrics. Several different ways of computing bootstrap P values are discussed, including the double bootstrap and the fast double bootstrap. It is emphasized that there are many different procedures for generating bootstrap samples for regression models and other types of model. As an illustration, a simulation experiment examines the performance of several methods of bootstrapping the supF test for structural change with an unknown break point. |
| Keywords: | bootstrap test, supF test, wild bootstrap, pairs bootstrap, moving block bootstrap, residual bootstrap, bootstrap P value |
| JEL: | C12 C15 |
| Date: | 2007–06 |
| URL: | http://d.repec.org/n?u=RePEc:qed:wpaper:1127&r=ict |