Article history: Received 8 March 2007 Received in revised form 14 October 2009 Accepted 20 October 2009 Available online xxxx JEL classification: D24 L63 L86

We report on novel mutations in the malK gene of Salmonella enterica serovar Typhimurium, encoding the ATPase subunit of the maltose transporter (MalFGK(2)). Biochemical analysis suggests that (i) L86 might be involved in a signaling step during substrate translocation and (ii) E306 may be critical for the structural integrity of the protein.

This paper examines a model in which position auctions influence consumer search. Both the selection of firms to include and the ordering of firms affect the efficiency of consumer search. Implications for reserve prices, click-through weights, and product variety are discussed. A two-stage auction mechanism is proposed. JEL Classification No.: D44, L86, M37

This paper uses data collected from eBay’s website to identify why buyers fail to leave (negative) feedback in online markets. Empirical results confirm that the fear of retaliation may be an important motivation for buyers not to leave (negative) feedback, while the time and effort cost of reporting may be not. keywords: reputation, feedback, asymmetric information JEL classification: L81; L86

The objective of this paper is to present a unifying framework for studying the impact of new collaborative technologies (or consumer technologies) on markets, society and economic science. It aims to influence researchers in social sciences, entrepreneurs and policy-makers to accelerate the adoption of the learning, tools and opportunities which the new collaborative technologies bring into th...

We model digital platforms as attention brokers that have proprietary information about their users’ product preferences and sell targeted ad space to retail industries. Retail producers—incumbents or entrants—compete for access this bottleneck. discuss when increased concentration among results in a tightening of the bottleneck, leading higher prices, fewer ads being sold entrants, lower consu...

Using data from a unique pricing experiment, we test Vickrey’s conjecture that responsive pricing can be used to smooth demand shocks. Our evidence shows that increasing the responsiveness of price to demand conditions reduces the magnitude of deviations in capacity utilization rates from a pre-determined target level. We discuss implications for the use of demand-side incentives to deal with c...

When a user shares her data with online platforms, she reveals information about others. In such setting, externalities depress the price of because once user's is leaked by others, has less reason to protect and privacy. These depressed prices lead excessive sharing. We characterize conditions under which shutting down markets improves welfare. Platform competition does not redress problem exc...

We develop a model to study the implications of a legal environment on the organization of software production. We show that contract enforcement a®ects the organizational mode (i.e., in-house versus outsourcing) of customized software development while copyright protection determines the introduction of package software. When copyright protection is weak, only customized software will be devel...

Open source software, developed by volunteers, appears counter to the conventional wisdom that without ownership rights or government intervention, public goods will not be efficiently provided. But complexity makes a difference: contracts are incomplete and ownership rights do not necessarily elicit socially optimal effort. I consider three mechanisms that improve the provision of complex soft...