BACKGROUND AND PURPOSE Our purpose was to evaluate the cost-effectiveness of clinical versus radiographic screening for an orbital foreign body before MR imaging. METHODS Costs of screening were determined on the basis of published reports, disability rating guides, and a practice survey. Base case estimates were derived from published guidelines. A single-state change model was constructed u...

Combinatorial auctions have been used in procurement markets with economies of scope. Preference elicitation is already a problem in single-unit combinatorial auctions, but it becomes prohibitive even for small instances of multiunit combinatorial auctions, as suppliers cannot be expected to enumerate a sufficient number of bids that would allow an auctioneer to find the efficient allocation. A...

Intertemporal preferences are di¢ cult to measure. We estimate time preferences using a structural bu¤er stock consumption model and the Method of Simulated Moments. The model includes stochastic labor income, liquidity constraints, child and adult dependents, liquid and illiquid assets, revolving credit, retirement, and discount functions that allow short-run and longrun discount rates to di¤e...

In this article we develop alternative ways to compare asset pricing models when it is understood that their implied stochastic discount factors do not price all portfolios correctly. Unlike comparisons based on x2 statistics associated with null hypotheses that models are correct, our measures of model performance do not reward variability of discount factor proxies. One of our measures is des...

The objective of this paper is to adopt a general equilibrium model and determine the socially e¢ cient discount factor, risk free rate and discount rate when there are heterogeneous anticipations about the growth of the economy as well as heterogeneous time preference rates. Among others we tackle the following questions. Is the socially e¢ cient discount factor an arithmetic average of the in...

In general terms, decreasing impatience means decreasing discount rates. This property has been usually referred to as hyperbolic discounting, although there are other discount functions which also exhibit decreasing discount rates. This paper focuses on the measurement of the impatience associated with a discount function with the aim of establishing a methodology to compare this characteristi...

This article considers a new concept of social optimum for an economy populated by agents with heterogeneous discount factors. It is based upon an approach that constrains decision rules to be temporally consistent: these are stationary and unequivocally ruled by the state variable. For agents who differ only in their discount factors and have equal weights in the planner’s objective, the tempo...

gent claims. The ~wo factors are the instantaneous riskless (short-term) interest rate and the instantaneous variance of changes in this short-term interest rate. The model is attractive not only because it provides for closed form expressions in a two-factor world. but also because it explicitly allows for a stochastic volatility f.lctOr. As the parameters of the model can be estimated using b...

BACKGROUND In cost-effectiveness analysis, discount rates are used in calculating the value of future costs and benefits. However, standard discount rates may not accurately describe the decision-making of patients with ulcerative colitis (UC). These patients often choose the long-term risks of immunosuppressive therapy over the short-term risks of colectomy, demonstrating very high discount ra...