Critical juncture theoryCritical juncture theory focuses on critical junctures, i.e., large, rapid, discontinuous changes, and the long-term causal effect or historical legacy of these changes. Critical junctures are turning points that alter the course of evolution of some entity (e.g., a species, a society). Critical juncture theory seeks to explain both (1) the historical origin and maintenance of social order, and (2) the occurrence of social change through sudden, big leaps. Critical juncture theory is not a general theory of social order and change.
Network effectIn economics, a network effect (also called network externality or demand-side economies of scale) is the phenomenon by which the value or utility a user derives from a good or service depends on the number of users of compatible products. Network effects are typically positive, resulting in a given user deriving more value from a product as more users join the same network. The adoption of a product by an additional user can be broken into two effects: an increase in the value to all other users (total effect) and also the enhancement of other non-users' motivation for using the product (marginal effect).
NAIRUNon-accelerating inflation rate of unemployment (NAIRU) is a theoretical level of unemployment below which inflation would be expected to rise. It was first introduced as NIRU (non-inflationary rate of unemployment) by Franco Modigliani and Lucas Papademos in 1975, as an improvement over the "natural rate of unemployment" concept, which was proposed earlier by Milton Friedman. In the United States, estimates of NAIRU typically range between 5 and 6%.
Vendor lock-inIn economics, vendor lock-in, also known as proprietary lock-in or customer lock-in, makes a customer dependent on a vendor for products, unable to use another vendor without substantial switching costs. The use of open standards and alternative options makes systems tolerant of change, so that decisions can be postponed until more information is available or unforeseen events are addressed. Vendor lock-in does the opposite: it makes it difficult to move from one solution to another.
Institutional economicsInstitutional economics focuses on understanding the role of the evolutionary process and the role of institutions in shaping economic behavior. Its original focus lay in Thorstein Veblen's instinct-oriented dichotomy between technology on the one side and the "ceremonial" sphere of society on the other. Its name and core elements trace back to a 1919 American Economic Review article by Walton H. Hamilton. Institutional economics emphasizes a broader study of institutions and views markets as a result of the complex interaction of these various institutions (e.
