By incorporating reciprocity in an otherwise standard principalagent model, I investigate the relation between monetary gift-exchange and incentive pay, while allowing for worker heterogeneity. I assume that some, but not all, workers care more for their principal when they are convinced that the principal cares for them. The principal can be egoistic or altruistic. Absent worker heterogeneity,...

Generalized frameworks for constructing intelligent tutors, such as GIFT promise many benefits. These benefits should be extended to systems that work in ill-defined domains, especially in simulation environments. This paper presents ideas for understanding how ill-defined domains change the tutoring dynamic in simulated environments and proposes some initial extensions to GIFT that accommodate...

If the bene ciary of an altruist's gift can be expected to use this gift e ciently, then a pure altruist (one who cares about the bene ciary's utility level, but not how utility is obtained) should only give gifts of money. This is often interpreted to mean that any other type of gift is evidence of paternal altruism. However, it is known (Linbeck and Weibull (1988)) that altruism creates an in...

BACKGROUND In the UK, altruism has featured explicitly as an underpinning principle for biobanking. However, conceptualizing donation as altruistic downplays the role of reciprocity and personal or family benefit. OBJECTIVE To investigate how biosample donors talk about their donation and whether they regard samples as 'gifts'. METHODS In this qualitative study, 21 people, both healthy volu...

A particular system of brain mechanisms, called the retinoid system, is proposed as the evolutionary adaptation responsible for the existence of subjectivity and our sense of being here in a surrounding 3D world. The structural and dynamic properties of the retinoid system successfully predict a novel conscious experience in which the brain constructs a vivid visual representation of an object ...

The Population Debate W ith around four babies born every minute, Philippine population is expected to hit 84.2 million by the end of the year. Growing at an average of 2.3% annually, the country’s population has increased fourfold since the 1950s. It now ranks 14th in the world in terms of population size and 8th in terms of population density. This phenomenon is seen either as an onus or a gi...

Why do individuals volunteer their time even when recipients receive far less value than the donor’s opportunity cost? Previous models of altruism that focus on the overall impact of a gift cannot rationalize this behavior, despite its prevalence. We develop a model that relaxes this assumption, allowing for differential warm glow depending on the form of the donation. In a series of laboratory...

Charitable Giving as a Gift Exchange: Evidence from a Field Experiment This study reports data from a field experiment that was conducted to investigate the relevance of gift-exchange for charitable giving. Roughly 10,000 solicitation letters were sent to potential donors in the experiment. One third of the letters contained no gift, one third contained a small gift and one third contained a la...

Polyandrous females are expected to discriminate among males through postcopulatory cryptic mate choice. Yet, there is surprisingly little unequivocal evidence for female-mediated cryptic sperm choice. In species in which nuptial gifts facilitate mating, females may gain indirect benefits through preferential storage of sperm from gift-giving males if the gift signals male quality. We tested th...

This paper asks whether gift exchange generates externalities for people outside of the bilateral relationship between the gift giver and recipient, and whether the nature of this relationship is affected by social networks. We examine this question in the context of a field experiment in urban Chinese hospital outpatient clinics. We first show that when patients give a small gift, doctors reci...