Today's online marketplaces for goods and services are imperfect. Participants make an initial post expressing their intention to buy or sell an object, but all offers on this post are private. These offers can be seen as expressions of other participants' intentions to buy or sell the same item. What if these offers were as public as the initial post? Would this decrease market friction and enable participants to close transactions more efficiently? What if every post and offer were tagged with a location enabling a real-time proximal picture of supply and demand? In this thesis, we explore a different kind of marketplace, a broadcast marketplace, where a combination of public post, proximal awareness and mobility decrease the friction of information flow and facilitate efficiency. This thesis explores the design, implementation and deployment of a system which enables users to efficiently view, understand and act upon this proximal picture of supply and demand. To test the viability of the broadcast marketplace we deployed Peddl, an implementation of the idea, in the MIT and Cambridge, MA community. Over the course of the trial we collected data on 5,839 unique visitors and 805 registered users, who made 726 posts totaling $234,913 in value. From this data we show that the additional transparency of supply and demand afforded by our design results in increased marketplace activity.

This book is an effort to tell the story of the last twenty-five years of television news in the context of the social and cultural history of American broadcasting. "Trash television" does not emerge from a vacuum; neither do broadcasts of the highest quality.

In order for free expression to be meaningful, there must be forums available for individuals wishing to express themselves. Despite an increasing number of broadcast stations, there are still far more people wishing to speak than there are licenses. This book examines the marketplaces for free speech and proposes means by which speaking opportunities can be increased. The author even proposes the creation of broadcast access channels. Unlike access proposals of the past, these channels would respect the rights of broadcasters and cable operators by not requiring them to accomodate speakers, but, rather, by establishing electronic soapboxes, open to speakers on a first-come basis, reflecting the traditional speech making in parks and on street corners. Caristi begins his work by examining the various freedom of expression theories. He asserts that of all the values protected, free expression as self-fulfillment is the most expansive and should be the approach adopted whenever possible. Through legal history and analysis, the book examines the cases and commentary relevant to public forum and broadcast cases. Red Lion, Tornillo, and their progeny are examined for rationale in regulating media. Despite claims to the contrary, scarcity is seen as an appropriate regulatory approach for broadcasting. This book is a valuable contribution to the discussion of first amendment and communication policy, and it should be of interest to students in communication, law, and public policy.