Do firms have adequate incentives to invest in protection against a risk whose magnitude depends in the actions of others? This paper characterizes the Nash equilibria for this type of interaction between agents, which we call the interdependent security (IDS) problem. When agents are identical, there are two Nash equilibria for a wide range of cost and risk parameters --- either everyone invests in protection or no one does. In some situations the incentive to invest in protection approaches zero as the number of unprotected agents increases. We develop an IDS model by first focusing on airline security and comparing the structure of this problem with other IDS examples such as computer security, fire protection, vaccinations, protection against bankruptcy, and theft protection. The paper also examines the roles of insurance, liability, fines and subsidies, third party inspections, regulations and coordinating mechanisms for internalizing the negative externalities characteristic of these problems. The concluding section suggests directions for future theoretical and empirical research.

The “tragedy of the commons ” metaphor helps explain why people overuse shared resources. However, the recent proliferation of intellectual property rights in biomedical research suggests a different tragedy, an “anticommons ” in which people underuse scarce resources because too many owners can block each other. Privatization of biomedical research must be more carefully deployed to sustain both upstream research and downstream product development. Otherwise, more intellectual property rights may lead paradoxically to fewer useful products for improving human health.

This paper uses the growing volume of scholarly work on ‘water and politics ’ to conceptually and methodologically frame an approach to the social analysis of water resources management. This paper sets out the thrust and focus of such a ‘political sociology of water resources management’. The framing draws theoretical insights from sociology, development studies, and, obviously, water resources studies. The main theoretical inputs are: a) critical realism as the general ontological and epistemological foundation (Bhaskar, 1989; Sayer, 1984); b) sociological theory on structure-agency dynamics (Giddens, 1984; Archer, 1995) and the notion of public sociology (Burawoy, 2005a); development studies ’ understanding of the different meanings of ‘development ’ (Thomas, 2000); d) theory on politics and social power (Kerkvliet, 1990; Lukes, 2005); and e) my own reading of the water resources literature through the lens of the boundary concept of ‘water control’. The structure of the paper is as follows. Section 1 explains where the attempt at defining a field of water resources management studies in this particular way comes from. The section situates the field in relation to development sociology as the intersection of sociology and development studies; discusses how the notions of discipline and scientific community help to understand the field’s characteristics; and briefly presents my own intellectual trajectory as part of this account. Section 2 discusses the object of a political sociology of water resources management. That discussion has four

Using data from the Tanzania Social Capital and Poverty Survey (SCPS), a large scale survey which asked individuals about the extent and characteristics of their associational activity and their trust in various institutions and individuals, we construct a measure of “social capital ” in rural Tanzania. By matching this measure of social capital with data on household incomes in the same villages both from the SCPS and an earlier household survey, the Human Resources Development Survey (HRDS) we show that “social capital ” is indeed both capital, in that it raises incomes, and social, in that household outcomes depend on village not just household social capital. The magnitude of social capital’s effect on incomes is impressively large: a one standard deviation increase in village social capital increases household expenditures per person (a proxy for income) by at least 20 to 30 percent. This impact is as large as an equivalent increase in non-farming assets or tripling the level of education. The data from the two surveys also allow the identification of some of the proximate channels through which social capital affects incomes: better publicly provided services, greater use of modern agricultural inputs, more community activity, and greater use of credit in agriculture. The findings, interpretations, and conclusions expressed and in this paper are entirely those of the authors. They do not necessarily reflect the views of the World Bank, its Executive Directors, or the countries they represent. 1

Most economic models are based on the self-interest hypothesis that assumes that all people are exclusively motivated by their material self-interest. In recent years experimental economists have gathered overwhelming evidence that systematically refutes the self-interest hypothesis and suggests that many people are strongly motivated by concerns for fairness and reciprocity. Moreover, several theoretical papers have been written showing that the observed phenomena can be explained in a rigorous and tractable manner. These theories in turn induced a new wave of experimental research offering additional exciting insights into the nature of preferences and into the relative performance of competing theories of fairness. The purpose of this paper is to review these recent developments, to

Social resources like trust and shared identity make it easier for people to work and play together. Such social resources are sometimes referred to as social capital. Thirty years ago, Americans built social capital as a side effect of participation in civic organizations and social activities, including bowling leagues. Today, they do so far less frequently (Putnam 2000). HCI researchers and practitioners need to find new ways for people to interact that will generate even more social capital than bowling together does. A new theoretical construct, SocioTechnical Capital, provides a framework for generating and evaluating technology-mediated social relations.

This paper explores the patterns and determinants of empowerment, income generation, and environmental sustainability under varying degrees of woodlot management in Tigray, Ethiopia. Our analysis is based upon a survey of 120 collectively managed woodlots, devolved to varying degrees, and 66 households that have recently received small plots of community land for tree planting. We find that more devolved woodlot

Theorists often speculate why open source and free software project contributors give their work away. Although contributors make their work publicly available, they do not forfeit their rights to it. Community managed software projects protect their work by using several legal and normative tactics, which should not be conflated with a disregard for or neglect of intellectual property rights. These tactics allow a project's intellectual property to be publicly and freely available and yet, governable. Exploration of this seemingly contradictory state may provide new insight into governance models for the management of digital intellectual property. Key Words: Software, Public Goods, Open Source, Intellectual Property, Common Pool Resources *Contact: Siobhn O'Mahony; Negotiations, Organization and Markets group, Harvard Business School, Baker Library West 186, Soldiers Field, Boston, MA 02163, USA; Tel: +1 617 495 0875; Fax: +1 617 496 7379; E-mail: somahony@hbs.edu This research was in part supported by the Stanford University's Center for Work, Technology and Organization, the Stanford Technology Ventures Program, and funds provided by the Alfred P. Sloan Foundation for the Social Science Research Council's Program on the Corporation as a Social Institution. Special thanks to the editors and reviewers for their helpful comments, to my informants for their time and interest and to Stephen Barley, Robert Sutton, Josh Lerner, Carliss Baldwin, George Baker, Victor Seidel, Fabrizio Ferraro, Mark Mortensen, Michael Schrage, Rachel Campagna and Jason Owen-Smith for their always thoughtful comments on the formation of these ideas and earlier versions of this paper. It's kind of cool to bring the power to where it belongs and what's really exciting about working with the hack...

The focus of this paper is to review what is known about free and open source software development (FOSSD) work practices, development processes, project and community dynamics, and other socio-technical relationships. It focuses on exploring how FOSS is developed and evolved based on an extensive review of a set of empirical studies of FOSSD projects that articulate different levels of analysis. These characterize what has been analyzed in FOSSD studies across levels that examine (i) why individuals participate; (ii) resources and capabilities supporting development activities; (iii) how cooperation, coordination, and control are realized in projects; (iv) alliance formation and inter-project social networking; (v) FOSS as a multi-project software ecosystem, and (vi) FOSS as a social movement. Next, there is a discussion of limitations and constraints in the FOSSD studies so far. Last, attention shifts to identifying emerging opportunities for future FOSSD studies that can give rise to the development of new software engineering tools or techniques, as well as to new empirical studies of software development.

the Wharton Risk Management and Decision Processes Center and the Columbia University Earth Institute. We are particularly grateful to Richard Zeckhauser for helpful discussion and comments on an earlier draft. Mark Broadie, Ido Erev, Victor Goldberg, Daniel Kahneman, Paul Kleindorfer and Yechiam Yemini and participants in the NBER Insurance Project Workshop, where this paper was presented, also provided useful insights. 1 Do firms have adequate incentives to invest in anti-terrorism mechanisms? This paper develops a framework for addressing this issue when the security choices by one agent affect the risks faced by others. We utilize the airline security problem to illustrate how the incentive by one airline to invest in baggage checking is affected by the decisions made by others. Specifically if an airline believes that others will not invest in security systems it has much less economic incentive to do so on its own. Private sector mechanisms such as insurance and liability will not necessarily lead to an efficient outcome. To induce adoption of security measures one must turn to regulation, taxation or institutional coordinating mechanisms such as industry associations. We compare the airline security example with problems having a similar structure (i.e., computer security and fire protection) as well as those with different structures (i.e., theft protection and vaccinations). The paper concludes with suggestions for future research.