Reasons and Means to Model Preferences as Incomplete

Literature involving preferences of artificial agents or human beings often assume their preferences can be represented using a complete transitive binary relation. Much has been written however on different models of preferences. We review some of the reasons that have been put forward to justify more complex modeling, and review some of the techniques that have been proposed to obtain models of such preferences

Prospect theory and tax evasion: a reconsideration of the Yitzhaki puzzle

The standard expected utility (EUT) model of tax evasion predicts that evasion is decreasing in the marginal tax rate (the Yitzhaki puzzle). Recent literature shows cases in which incorporating prospect theory (PT) does and does not overturn the Puzzle. In a general environment that nests both PT and EUT preferences, we provide a detailed study of how the elements of PT affect the Puzzle. PT does not always reverse the Puzzle, hence we give and interpret conditions for when it does and does not. When allowing for stigma and/or variable audit probability, PT reverses the Puzzle in the same way and with the same limitations as does EUT, if equally augmented

State dependent choice

We propose a theory of choices that are influenced by the psychological state of the agent. The central hypothesis is that the psychological state controls the urgency of the attributes sought by the decision maker in the available alternatives. While state dependent choice is less restricted than rational choice, our model does have empirical content, expressed by simple "revealed preference" type of constraints on observable choice data. We demonstrate the applicability of simple versions of the framework to economic contexts. We show in particular that it can explain widely researched anomalies in the labour supply of taxi drivers

Manipulation of Choice Behavior

We introduce and study the problem of manipulation of choice behavior. In a class of two-stage models of decision making, with the agent's choices determined by three psychological variables, we imagine that a subset of these variables can be selected by a manipulator. To what extent does this confer control of the agent's behavior? Within the specified framework, which overlaps with two existing models of choice under cognitive constraints, we provide a complete answer to this question

The relationship between arthritis and human parvovirus B19 infection

In order to evaluate the role of human parvovirus B19 in the etiopathogenesis of autoimmune diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), synovial fluid and blood specimens were collected at 1-month intervals from 20 patients with early synovitis (ES) and 31 with RA. Blood specimens were also collected from 25 patients with SLE, 25 with osteoarthritis (OA) as the diseased control group, and 50 healthy blood donors (HBD) as the healthy control group. Detection of B19 IgM and B19 IgG were performed by enzyme-linked immunosorbent assay from serum specimens, and B19 DNA was detected by polymerase chain reaction from synovial fluid samples. B19 IgM, B19 IgG, and B19 DNA were found in the three patients of the ES group. Subsequently, two of them were diagnosed with RA and one with SLE. B19 DNA was also detected in the synovial fluid of eight patients in the RA group. Of them, all were positive for B19 IgG and half were positive for B19 IgM. B19 IgM was not detected in either of the control groups. To define the role of B19 in the etiopathogenesis and prognosis of undiagnosed arthritis and other chronic inflammatory diseases such as RA and SLE, we need broader serial and prospective studies based on clinical and laboratory collaboration. In conjunction with case reports, these studies would also serve to detect other possible factors in the etiopathogenesis of chronic inflammatory diseases