Static Equilibrium Concept Research Articles

Of scientists and superheroes: Educational television and pretend play as preparation for science learning

Children aged 4 to 7 (N = 119; 50.4% female, 87.4% White) watched an educational video containing unrealistic elements (i.e., superpowered scientists). Before or after this video, they participated in a hands-on science activity under one form of pretense (i.e., act like a scientist vs. superhero) or under no pretense. Both interventions imparted information about the concept of static equilibrium. Results indicated that children's understanding of static equilibrium improved more when they watched the video before (vs. after) the hands-on activity. Age moderated this effect on one measure of learning, such that 5- and 6-year-olds benefitted more than 4- and 7-year-olds from watching the video first. Gender did not emerge as a moderator, and the pretense manipulation had no impact on children's responses. These results suggest that educational videos can prepare children to learn from hands-on science activities, even when those videos contain unrealistic elements.

Headland-Bay Beaches: Static Equilibrium Concept for Shoreline Management

Headland-Bay Beaches: Static Equilibrium Concept for Shoreline Management

Social Learning Equilibria

We consider a large class of social learning models in which a group of agents face uncertainty regarding a state of the world, share the same utility function, observe private signals, and interact in a general dynamic setting. We introduce social learning equilibria, a static equilibrium concept that abstracts away from the details of the given extensive form, but nevertheless captures the corresponding asymptotic equilibrium behavior. We establish general conditions for agreement, herding, and information aggregation in equilibrium, highlighting a connection between agreement and information aggregation.

Social Learning Equilibria

We consider a large class of social learning models in which a group of agents face uncertainty regarding a state of the world, share the same utility function, observe private signals, and interact in a general dynamic setting. We introduce Social Learning Equilibria, a static equilibrium concept that abstracts away from the details of the given extensive form, but nevertheless captures the corresponding asymptotic equilibrium behavior. We establish general conditions for agreement, herding, and information aggregation in equilibrium, highlighting a connection between agreement and information aggregation.

Students’ difficulties with tension in massless strings

Many students enrolled in introductory mechanics courses have difficulties with understanding the concept of static equilibrium. Some of these difficulties are related to the concept of force in the context of tension in massless strings. We identify three kinds of misconceptions: Students’ beliefs that the angle of the string and proximity to the object are related to the tension. Students also use incorrect compensation arguments to reason about situations where both the angle and proximity change simultaneously. These difficulties were identified during investigations conducted in laboratory and lecture sessions at three universities in the United States and Mexico.

A study on effects of market systems in an artificial market

In an artificial market approach with multi-agent systems, the static equilibrium concept is often used in market systems to approximate continuous market auctions. However, differences between the static equilibrium concept and continuous auctions have not been discussed in the context of an artificial market study. In this paper, we construct an artificial market model with both of them, namely, the Itayose and Zaraba method, and show simple characteristic differences between these methods based on computer simulations. The result indicates the further need to model the market system by studying artificial markets.

Viability and Equilibrium: ISLM Revisited

More than fifty years after the publication of Keynes' General Theory and of the review article by Hicks, ISLM remains the basic model for teaching Keynesian macroeconomics. Some Keynesians have rightly insisted on the inadequacies of ISLM in capturing Keynes' thought but have not converted the profession to their views. The same fate may befall this paper whose aim is to suggest an alternative class-room model in the Keynesian and Kaleckian tradition. Nevertheless, in accordance with Orange's lucid motto,il n'est pas necessaire d'esperer pour entreprendre ni de reussir pour perseverer... The main thesis is that the concept of static equilibrium, central to ISLM, is not adequate to express the most fundamental aspect of the Keynesian revolution. The first section of the paper is devoted to a defense of the more general concept of viability. Static equilibrium will appear as but one particular example of this larger notion. A very simple model is presented in the second section. Its distinctive feature, aside from its inclusion of the ISLM equations, is to make a clear distinction between the macroeconomic relations exhibiting the consequences of the decisions of the agents on the one hand and the principles according to which these decisions are taken and carried out on the other. The concept of static equilibrium, by contrast is founded on the confusion of the two: a necessary condition for individual actions to be effective is their mutual compatibility. The third section deals very briefly with the implications of the model for the analysis of macroeconomic policy.

Load distribution in moving furniture

Static equilibrium conditions are applied to the case of moving a piece of furniture. Assume that two people are carrying a piece of furniture down a hill with a uniform speed. The load distribution on both people is found to be a function of the slope of the hill, the difference in the heights of the two people, the length of the furniture, and, more importantly, the force angle that the person at the upper end applied relative to a horizontal line. Some interesting features are revealed through this analysis. For example, contradictory to our common sense, the person at the lower end does not always carry more ‘‘weight.’’ This problem was found to be effective in helping students develop the static equilibrium concept.

BORK'S PARADOX: STATIC VS. DYNAMIC EFFICIENCY IN ANTITRUST ANALYSIS

Judge Robert Bork holds two opposing attitudes towards perfect competition. It is a highly useful economic model for illustrating allocative efficiency, but it is a defective policy model because it deliberately omits productive efficiency. He reconciles these attitudes by combining perfectly competitive allocative efficiency with dynamically competitive productive efficiency in his analysis.However, these two kinds of competition do not readily mix. One is a static equilibrium concept, the other a dynamic disequilibrium concept. One assumes perfect knowledge and the absence of change; the other assumes imperfect knowledge, learning, and continual flux. Each kind of competition is built on assumptions which, if true, would preclude the existence of the other.Bork's policy conclusions require the simultaneous existence of both kinds of competition. If he drops dynamic competition from the analysis, a much more stringent antitrust policy is called for. If he drops static competition, economic theory does not justify even his strictures against mergers and cartels.

Winners, blockers, and the status quo: Simple collective decision games and the core

This essay considers a general class of collective decision problems that may be represented as simple collective decision games. This analysis departs from the emphasis of the earlier literature on simple cooperative games by giving special attention to situations in which blocking coalitions are possible. We define a procedure for constructing the core of such games. We establish results demonstrating that, in simple games in which blocking coalitions are possible, the relative attractiveness of the no-decision or status quo outcome delimits the core. We prove theorems specifying necessary and sufficient conditions for any simple collective decision game to possess a nonempty core and for the status quo to belong to the core. The last theorem in this essay has special significance for solution theory about simple collective decision games. Any point in the core has a claim for stability if that point somehow becomes the tentative outcome of negotiations. But, mathematically, the core is a static equilibrium concept that, as such, does not specify a process leading to any feasible alternative as the tentative outcome. However, the status quo is the natural starting point of negotiations in collective decision making. Therefore, one can make a special claim for the stability of the status quo if it belongs to the core.

TIME IN ECONOMIC THEORY

Everyday, in real life, the past is irrevocable and the future predicted with a margin of uncertainty. In a theoretical model, time can be frozen but it is a common error to confuse a comparison of static positions with a movement between them. E. H. Carr claims that historians and natural scientist are alike in having given up the search for grand ‘laws’ and are now content to try to learn ‘how things happen’. To improve the status of economics it is necessary to get rid of logical contradictions, which involves eliminating the concept of static equilibrium; to guard against conception by ideological prejudice and to use the study of history, as it unfolds, to check up on the hypotheses that theory suggests.