Although response effort is considered a dimension of the cost to obtain reinforcement, little research has examined the economic impact of effort on demand for food. The goal of the present study was to explore the relationship between effort and demand. Three Sprague Dawley rats were trained to press a force transducer under a series of fixed-ratio schedules (1, 10, 18, 32, 56, 100, 180, 320, and 560) under different force requirements (5.6 g and 56 g). Thus, nominal unit price (responses / food) remained constant while minimal response force requirements varied. Using a force transducer allowed the measurement of responses failing to meet the minimal force requirement (i.e. “subcriterion responses”), an advantage over prior approaches using weighted levers to manipulate effort. Consistent with prior research, increasing the unit price decreased food consumption, and raising minimum force requirements further reduced demand for food. Additionally, increasing the force requirement produced subcriterion responses. Analysis indicated that subcriterion responses did not create incidental changes in unit price. Obtained force data revealed that including obtained forces in unit price calculations provided better predictions of consumption when compared to using criterion force requirements.

Avec l’avènement progressif de l’ère industrielle, l’activité de l’homme a pesé de plus en plus négativement sur l’équilibre des milieux naturels. Il s’en est suivi la construction progressive d’un droit répressif de l’environnement, destiné à lutter contre les atteintes à la nature, mais chroniquement élaboré sur les bases même d’un dispositif de police administrative, un concept assis sur les fondements d’un droit résolument disciplinaire, structurellement et moralement insuffisant pour révéler une valeur essentielle. La responsabilité délictuelle ainsi que le régime de responsabilité environnementale visent à inventer de nouveaux concepts juridiques afin de réparer les atteintes à la nature, mais révèlent de nombreuses limites. Dans ce contexte, la norme pénale, se voulant surtout utilitariste, est à la fois auxiliaire d’un droit administratif et auxiliaire de normes réparatrices, et, demeure sans influence pour faire émerger la valeur réelle de l’intérêt protégé. Il ressort d'une telle analyse que la protection de la nature, en tant que valeur essentielle, ne peut être consacrée que par le recours à un droit pénal efficace établi sur les bases de fondements éthiques compris et acceptés par tous. Cette thèse de droit interne s’inscrit dans une démarche prospective qui voudrait concourir à un tel résultat en tentant de repenser et de restructurer le droit pénal spécial de l’environnement de manière à offrir au juge répressif la possibilité de porter un véritable jugement de valeur sur des atteintes désormais reconnues comme autodestructrices du genre humain lui-même. / With the gradual advent of the industrial era, human activity has weighed more negatively on the balance of natural environments. This was followed by the gradual construction of a very repressive law for environment, intended to combat prejudice against nature, but chronically prepared on the very bases of administrative police, a seated concept on the basis of a resolutely disciplinary law, structurally and morally insufficient to reveal an essential value. Tort, as well as environmental liability regime aim to invent new legal concepts in order to redress the damage to nature, but they reveal many limitations.In this context, the criminal standard, meant to be especially utilitarian, is both an auxiliary of administrative right and an auxiliary of remedial standards, and remains without influence in bringing out the real value of the protected interest.It is such an analysis that the protection of nature, as an essential value, may be used only by recourse to an effective criminal law established on the bases of ethical foundations understood and accepted by everybody. This thesis of law fits into a forward-looking approach that would contribute to such an outcome by trying to rethink and restructure the special criminal law of the environment so as to offer the repressive judge the opportunity to exercise a true value judgment on self-destructive and now recognized violations of mankind itself.