The paper reviews the literature on the characteristics and impact of opinion leaders on the diffusion of new knowledge, concluding that there is no clear evidence on whether opinion leaders are more effective if they are similar in socioeconomic attributes to the other farmers rather than superior to would be followers. A multivariate analysis of the changes in integrated pest management knowledge in Indonesia among follower farmers over the period 1991-98 indicates that opinion leaders who are superior to followers, but not excessively so, are more effective in transmitting knowledge. Excessive socioeconomic distance is shown to reduce the effectiveness of diffusion. The paper then derives operational implications of the empirical results.

Strategic management is a system of continual disequilibrium, with firms in a continual struggle for competitive advantage and relative fitness. Models that are dynamic in nature are required if we are to really understand the complex notion of sustainable competitive advantage. New tools are required to tackle challenges of how firms should compete in environments characterized by both exogeneous shocks and intense endogenous competition. Agent-based modelling of firms' strategies offers an alternative analytical approach, where individual firm or component parts of a firm are modelled, each with their own strategy. Where traditional models can assume homogeneity of actors, agent-based models simulate each firm individually. This allows experimentation of strategic moves, which is particularly important where reactions to strategic moves are non-trivial. This Element introduces agent-based models and their use within management, reviews the influential NK suite of models, and offers an agenda for the development of agent-based models in strategic management.

Since its development shaped by the turmoil of the World Wars and suspicion of new technologies such as film and radio, political communication has become a hybrid field largely devoted to connecting the dots among political rhetoric, politicians and leaders, voters' opinions, and media exposure to better understand how any one aspect can affect the others. In The Oxford Handbook of Political Communication Kate Kenski and Kathleen Hall Jamieson bring together leading scholars, including founders of the field of political communication Elihu Katz, Jay Blumler, Doris Graber, Max McCombs, and Thomas Paterson,to review the major findings about subjects ranging from the effects of political advertising and debates and understandings and misunderstandings of agenda setting, framing, and cultivation to the changing contours of social media use in politics and the functions of the press in a democratic system. The essays in this volume reveal that political communication is a hybrid field with complex ancestry, permeable boundaries, and interests that overlap with those of related fields such as political sociology, public opinion, rhetoric, neuroscience, and the new hybrid on the quad, media psychology. This comprehensive review of the political communication literature is an indispensible reference for scholars and students interested in the study of how, why, when, and with what effect humans make sense of symbolic exchanges about sharing and shared power. The sixty-two chapters in The Oxford Handbook of Political Communication contain an overview of past scholarship while providing critical reflection of its relevance in a changing media landscape and offering agendas for future research and innovation.

Now in its fifth edition, Diffusion of Innovations is a classic work on the spread of new ideas. In this renowned book, Everett M. Rogers, professor and chair of the Department of Communication & Journalism at the University of New Mexico, explains how new ideas spread via communication channels over time. Such innovations are initially perceived as uncertain and even risky. To overcome this uncertainty, most people seek out others like themselves who have already adopted the new idea. Thus the diffusion process consists of a few individuals who first adopt an innovation, then spread the word among their circle of acquaintances—a process which typically takes months or years. But there are exceptions: use of the Internet in the 1990s, for example, may have spread more rapidly than any other innovation in the history of humankind. Furthermore, the Internet is changing the very nature of diffusion by decreasing the importance of physical distance between people. The fifth edition addresses the spread of the Internet, and how it has transformed the way human beings communicate and adopt new ideas.