University of Nottingham

About: University of Nottingham is a education organization based out in Nottingham, Nottingham, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 54772 authors who have published 119600 publications receiving 4227408 citations. The organization is also known as: The University of Nottingham & University College, Nottingham.

The effect of rewards and sanctions in provision of public goods

Abstract: I. INTRODUCTION The experimental literature on voluntary public goods provision shows that groups attain better outcomes than implied by economic models based on individuals maximizing own-monetary earnings. At the same time, however, groups uniformly fail to achieve optimal outcomes, suggesting that incentives to free ride are important. Moreover, when the decision situation is repeated, the group outcome often deteriorates with repetition, suggesting that, in many settings, a group's ability to overcome free-rider incentives may be transitory as explained in Andreoni and Miller (1993), Croson (1998), Isaac, Walker, and Williams (1994). In this paper we report an experiment examining the impact of introducing opportunities for individuals to reward or sanction other group members after observing their decisions. This institutional change is motivated by the observation that such opportunities are commonplace in field settings. In many group or team situations, individuals observe the actions of others, and individuals often have rich opportunities for reacting to others' behavior in ways that may impose costs or benefits on both parties. There is abundant anecdotal evidence that individuals sanction those who engage in selfish activities at the expense of other group members. For example, people who violate social norms are often ostracized. Similarly, there is strong anecdotal evidence that people are prepared to make sacrifices to help others on a quid pro quo basis. (1) Recent experiments with simple proposer-responder games also demonstrate that responders are willing to depart from own-earnings maximization by rewarding more generous proposers or sanctioning less generous proposers as seen in Andreoni, Harbaugh, and Vesterlund (2003) and Offerman (2002). Given this evidence, it is quite plausible that individuals will sanction or reward other group members based upon their contributions to a public good in a laboratory setting. In turn, the possibility of receiving such sanctions or rewards may affect contributions. Such contributions could be viewed as a response to the threat of negative reciprocation, in the case of sanctions, or the expectation of positive reciprocation, in the case of rewards. Our experiment directly compares the effectiveness of such negative and positive reciprocation in maintaining contributions to public goods. (2) In our experiment, groups of four subjects make contribution decisions in a sequence of ten public goods games without opportunities to reward or sanction. These subjects then play an additional ten games in which a second stage is added at the end of each game. Depending on treatment, in the second stage, subjects are given an opportunity to reward, sanction, or both reward and sanction other group members on the basis of their contribution decisions. When neither rewards nor sanctions are available, our results mirror those of previous experiments: contributions and earnings steadily diminish with repetition. In the other treatments, the introductions of opportunities to reward and/or sanction initially increase contributions. However, in the reward treatment, contributions subsequently decrease to a level below that observed in the absence of opportunities to reward. Thus, the opportunity to reward by itself is insufficient to sustain contributions. In contrast, we find that sanctioning sustains public goods provision at a level above that observed in the absence of sanctioning opportunities, and so sanctioning appears to be a more effective mechanism for sustaining contributions. However, opportunities to sanction initially result in a loss of efficiency as the direct costs associated with sanctioning outweigh the effect of increased contributions. Only in later rounds, where it appears that the mere threat of being sanctioned sustains contributions, does the opportunity to sanction enhance group performance. Our treatment allowing both sanctions and rewards suggests a synergistic relationship between the two, insofar as this treatment generates the highest contributions and earnings. …

The IMAGEN study: reinforcement-related behaviour in normal brain function and psychopathology.

Abstract: The IMAGEN study: reinforcement-related behaviour in normal brain function and psychopathology

Effects of an intervention based on self-determination theory on self-reported leisure-time physical activity participation.

Abstract: Based on self-determination theory, the present study developed and evaluated the utility a school-based intervention to change pupils' physical activity intentions and self-reported leisure-time physical activity behaviour. The study evaluated utility of the intervention to promote physical activity participation over a 5-week interval of time. A cluster randomised design targeting 215 pupils from 10 schools with schools as the unit of randomisation was adopted (Male = 106, Female = 109, Age = 14.84, SD = 0.48). Results indicated that pupils who were taught by autonomy-supportive teachers reported stronger intentions to exercise during leisure time and participated more frequently in leisure-time physical activities than pupils in the control condition. Autonomous motivation and intentions mediated the effects of the intervention on self-reported physical activity behaviour. It is concluded that self-determination theory provides a useful framework for the development of school-based interventions that ultimately affect leisure-time physical activity participation.

Prognostic Significance of Nottingham Histologic Grade in Invasive Breast Carcinoma

Abstract: Purpose The three strongest prognostic determinants in operable breast cancer used in routine clinical practice are lymph node (LN) stage, primary tumor size, and histologic grade. However, grade is not included in the recent revision of the TNM staging system of breast cancer as its value is questioned in certain settings. Materials and Methods This study is based on a large and well-characterized consecutive series of operable breast cancer (2,219 cases), treated according to standard protocols in a single institution, with a long-term follow-up (median, 111 months) to assess the prognostic value of routine assessment of histologic grade using Nottingham histologic grading system. Results Histologic grade is strongly associated with both breast cancer–specific survival (BCSS) and disease-free survival (DFS) in the whole series as well as in different subgroups based on tumor size (pT1a, pT1b, pT1c, and pT2) and LN stages (pN0 and pN1 and pN2). Differences in survival were also noted between different in...