A test of four theories of coalition formation: Effects of payoffs and resources.

Used 3 coalition games to test the minimum resource, minimum power, and bargaining theories against each other and against equal excess theory; 144 male undergraduates were Ss. In Game X, all winning coalitions had the same payoffs but players had different resources; in Game Y, winning coalitions had different payoffs and players had different resources. The characteristic functions of the games (payoffs for the coalitions) were the same for Games Y and Z, and the resource distributions were the same for Games X and Z. Coalition behavior was virtually the same in Games Y and Z, but coalition behavior in these games differed from that in Game X. Thus, when there were differences in both coalition payoffs and individual resources, the payoffs rather than the resources tended to influence coalition behavior. Coalition behavior in Games Y and Z was best accounted for by equal excess theory, coalition behavior in Game X by bargaining theory. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bargaining strength as a function of coalition alternatives.

Previous research has shown that a person's bargaining strength in a coalition situation is a function of the number and size of alternative coalitions available to the bargainer and the value (expected profit) of these alternatives. The present study examined the effects of number and size of the alternatives on bargaining strength and tested the weighted probability and equal excess theories of coalition formation. The number and size of alternative coalitions were varied independently, and the value of each member in alternative coalitions was kept constant. 168 undergraduates were asked to bargain in 1 of 3 coalition games over a sequence of 6 trials. Results indicate that both number and size affected coalition outcomes: The number of alternatives primarily affected the payoff shares of the coalition members, whereas the size of alternatives primarily affected the frequencies of coalitions. Tests of the predictions of the weighted probability and equal excess models showed little support for either theory. Some restrictions on the generality of these models are suggested. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The functions of resources in coalition bargaining.

An important factor that distinguishes theories of coalition formation is their assumptions regarding the role of "resources" (Rs) in coalition bargaining. Two basic functions of Rs are hypothesized: a normative function, in which Rs provide a norm or frame of reference for a fair (equitable) division of rewards, and a strategic function, in which Rs affect the number and size of winning coalitions. It is shown that minimum R theory is based entirely on the normative function; minimum power and weighted probability models are based entirely on the strategic function; and bargaining theory and equal excess model are based on both functions. An experiment was conducted with 200 male undergraduates to contrast these theories in terms of the 2 functions of Rs. Results provide the greatest support for bargaining theory and equal excess model, and it is hypothesized that a theory that ignores one or the other function is not likely to yield accurate predictions. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of prior experience on coalition bargaining.

Tested S. S. Komorita's (see record 1981-01237-001) equal excess model. 126 male undergraduates played 3-person multivalued games. All groups played 4 trials of a test game either for points that were later converted to prizes or for money. Prior to the test game, triads in different conditions were exposed to a varying number of coalition games. Results show a large and significant effect on coalition payoffs: The greater the experience, the greater the deviation of payoffs from equal splits. Thus, the results of many coalition experiments may be restricted to naive bargainers and may not be generalized to experienced, sophisticated bargainers. (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generality and validity of some theories of coalition formation.

Although there have been numerous empirical tests of various theories of coalition formation, many of these data may be equivocal because the relative validity of a given theory may vary with the procedure used to test it. Accordingly, 3 different procedures, varying in communication restrictions and information availability, were used to test 3 theories of coalition formation: minimum resource theory, bargaining theory, and the weighted probability model. Group size (3, 4, and 5 members) was also varied. Based on data from 372 male undergraduates, the results indicate that group size and experimental procedure have significant effects on the validity of the 3 theories. The predictions of minimum resource theory were least accurate, whereas the predictions of the bargaining theory were most accurate. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Number of coalitions and resources as sources of power in coalition bargaining.

Investigated, using 80 female and 50 male undergraduates, the importance of 2 potential sources of power in coalition situations (number of coalitions in which the person is included and assigned resources), a potentially influential individual-differences factor (gender), and the validity of 4 theories of coalition formation (minimum power theory, the Roth-Shapely value, the weighted probability model, and bargaining theory). Five-person groups of males or females played 20 trials of a coalition game that varied the number of coalitions available to the players. Games were presented either with or without resources being assigned. Results indicate that both resources and number of alternatives influenced coalition outcomes. Players' payoffs were directly related to both factors, and coalition frequency was inversely related to the total number of alternatives available to the coalition members. Minor gender differences were also obtained. Implications for coalition theories in general and the weighted probability model in particular are discussed. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of group size and communication availability on coalition bargaining in a veto game.

Examined the effects of manipulating the size of groups of 250 male undergraduate negotiators and their ability to communicate with one another in a game in which 1 player held veto power (i.e., had to be included in any winning coalition). The predictions of 3 models (core, value, and weighted probability) were tested. The game, in which the veto player could form a winning coalition with any other single player, was repeated for a series of 10 winning coalitions (trials). The effects for group size indicate significant differences between 3-person groups and 4-, 5-, and 6-person groups, and between all of these groups and 7-person groups. The increasing payoffs over trials were significant in the no-communication conditions, but no significant increases occurred in the conditions in which communication was available. The increasing payoffs for the veto player when communication opportunities were not available yielded the only support for the predictions of the core model; the overall payoffs consistently supported the predictions of the value and the weighted probability models. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Test of the bargaining and equal excess theories of coalition formation: Effects of experience, information about payoffs, and monetary stakes.

Compared the bargaining and equal excess theories of coalition formation for their accuracy in predicting the effects of bargaining experience, information about coalition payoffs, and monetary stakes on coalition behavior in a 5-person game. 380 male undergraduates served as Ss. Manipulation of bargaining experience involved having each group play 4 trials of the game. Information about payoffs was varied by giving players in half the groups information about the payoffs for all the possible coalitions, and those in the other half of the groups information only about the payoffs for the coalitions of which they could be a member. Monetary stakes were manipulated by having Ss in half the groups play the game for the chance of winning $3, and Ss in the other half of the groups play the game for the chance of winning $50. Consistent with previous findings, monetary stakes had no effect on coalition behavior. Both bargaining experience and payoff information, however, had effects on coalition behavior, and these effects tended to support bargaining theory rather than equal excess theory. (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of cue exposure and deprivation on cognitive resources in smokers.

Examines the effects of manipulations designed to induce an urge to smoke on cognitive resources. Two cue-exposure experiments were conducted in which current smokers' reported urge to smoke and cognitive resources, as measured by a secondary reaction time (RT) probe, were assessed. In each study, Ss came to the laboratory twice, once while deprived of smoking for 12 hrs and once when they were nondeprived. During each session, Ss were exposed to both smoking and control cues. Results indicated that experimental manipulations designed to elicit a strong urge to smoke led to an increase in self-reported urge to smoke and a decrease of available cognitive resources, as measured by RT. In addition, these 2 measures were significantly correlated. These data, in conjunction with previous findings (M. A. Sayette et al, 1994) using alcohol-dependent Ss, lend support to the validity of RT as an objective measure of the effects of cue exposure on cognitive resources. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Level of aspiration in coalition bargaining.

Although some theories of coalition formation are quite accurate and promising, they are unable to explain the large variability of coalition outcomes. It is hypothesized that the variability of outcomes can be attributed to the variability of subjects' aspiration levels in coalition experiments. A bargainer with high aspirations is likely to make high demands and is likely to be rejected as a coalition partner. To manipulate aspiration level, the points-to-money conversion scales of subjects (105 college students) were systematically varied in three-person coalition games. As hypothesized, the results indicate that bargainers who have high aspirations (relative to other bargainers) are more likely to be excluded from coalitions. The implications of these results for current theories of coalition formation and for the development of a process theory are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Changes in outcomes in coalition bargaining.

Examined the results of earlier coalition experiments that concluded that the coalition with the largest payoff per member occurs most frequently and the reward division is close to an equal split (except for frequent deviations from equal share payoffs). The present authors hypothesized that inconsistencies in previous research were due to differences in experimental procedure and to Ss' familiarity with coalition games. In the present study, 240 male undergraduates played a 4-person multivalued apex game for 6 trials. Three games and 2 procedures were used. The 2 procedures differed in the number of rounds of offers and counteroffers required to form a coalition. As hypothesized, results indicate that deviations from equal shares increased over trials of the game and were greater with the procedure that required more rounds of bargaining. Findings regarding payoff divisions are in the direction predicted by the bargaining theory and equal excess model of coalition formation, but findings regarding frequencies of coalitions are contrary to the predictions of both theories. (40 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Considering the best choice: Effects of the salience and accessibility of alternatives on attitude–decision consistency.

The authors examined how the presence or absence of specified alternatives influences which alternatives are considered and what choice is made. The accessibility of alternatives as a moderator of the correspondence between attitudes and decisions also was investigated. In Study 1, the accessibility of alternatives was an important determinant of choice when decision options were unspecified. The results of Studies 2 and 3 suggest that the potential for attitude-decision correspondence is high when (a) the decision context makes the alternatives salient or (b) alternatives are easily accessed from memory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Community alternatives to psychotherapy.

Increasingly, individuals are turning to and being confronted by alternatives to dynamically-oriented therapy. Among these alternative change systems are alternative therapies such as Alcoholics Anonymous, and alternatives to therapy, such as the spiritual approaches based on various meditations. There are important theoretical conflicts between dynamic therapy and these alternatives. However, combinations of dynamic therapy and these alternatives are being forged by consumers of mental health services. In their effort to maximize the delivery of help, consumers make pragmatic decisions to construct such combinations, ignoring or deemphasizing theoretical conflicts or viewing them within a framework of complementarity. Research on these combinations is needed to learn more about which are effective with whom and for what purpose. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Diagnostic testing and the new alternatives.

Described and evaluated the experimental, the behavioral, the decision-making, and the operations-research models of assessment. The new models emphasize the importance of the relevance of psychological information for specific clinical decisions. They point to the need for closer participation of psychologists in everyday decision processes concerning treatment and other actions with remedial implications. (2 p. ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Management of calcaneonavicular coalition and results

26 cases of calcanconavicular coalitions were treated by resection of the calcanconavicular bar. The endresults were markedly influenced by the age at surgery, while there was no difference between the "bone" and "cartilage" group. The coalition must be recognised if someone examinates a rigid flatfoot.     

Effects of differential pretraining on learning-set formation in rhesus monkeys.

Compared the rate of learning-set formation by 4 rhesus monkeys that had previously been pretrained on the win-stay component of the learning-set strategy (Group WS) to the rate evidenced by 4 others that had pretraining on the lose-shift component (Group LS). Differences between groups were small, and asymptotic levels were below those previously obtained by monkeys without pretraining. The negative transfer resulted from generalized tendencies to perseverate or shift (Groups WS and LS, respectively), regardless of response outcome. The former tendency dissipated relatively rapidly, while the latter persisted very markedly throughout the 400-problem learning-set series. It is noted that learning-set formation requires a balance between the win-stay and lose-shift components; however, the optimal ratio is unknown. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Test of normality against skewed alternatives.

Describes a useful test of normality based on g1, the 3rd standardized sample moment. The test is computationally simple and has good sensitivity to nonnormality due to skewness. It is asymptotically the most powerful test of normality against deviations from normality due solely to skewness. 2 simple approximations to the test's null distribution are given. The 1st is a normal approximation valid for large samples, and the 2nd is a t transformation valid for sample sizes as small as 8. Some general comments concerning the use of tests of normality are also presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)