A model for estimating fish population and optimal fishing effort in lakes and rivers

We developed a model for estimating the fish population for various species in lakes and rivers. Our estimation focuses, in its first step, on fish species that breed outside the lake. Using the annual outside supply of fingerlings, natural survival rate and reported amounts of fish caught, we estimated fish stock. Given the estimated stock for fish bred outside the lake, we can evaluate the catch rate. Assuming equal catch rates for other species, and given the amount caught for each species, we are able to evaluate each species stock. Using the proposed technique, we evaluated various species stocks in the Sea of Galilee (Lake Kinneret) in Israel. Using our suggested technique for evaluating fish stock, we calculated the optimal effort of fishing needed for maximizing steady state profit of the fishers.     

Subjective evaluation of delayed risky outcomes for buying and selling positions: the behavioral approach

This paper analyzes time discounting as a function of risk, using reservation prices. Based on experimental data, we compare bidder reservation prices for riskless assets with those for risky assets. The experiments rely on a second price auction with real monetary incentives and real delay in payoffs. We estimate the pure time discount rate for different maturities, considering riskless assets (bonds) and risky assets (delayed lotteries). An innovation in the experimental design allows disentangling pure time from pure risk discounting effects. If subjects bid for assets, we find implied discount rates for risky assets to be uniformly lower than those for riskless assets, across all maturities (the risk moderation effect). However, there is no risk moderation effect if subjects quote ask prices. We argue that delaying a payoff has a stronger effect on the price of bonds than on the price of risky assets since, in the case of bonds, the investor moves from a position of certainty to a position of risk, or uncertainty. Our findings on the risk moderation effect may be used to explain the attractiveness of compensation contracts with options, as commonly used in the financial industry.     

RETESTING THE UNCERTAINTY EFFECT USING LOTTERIES WITH REAL PRODUCTS AND MONEY

In the current study, several experiments re‐examine the uncertainty effect using lotteries that include real products, monetary outcomes and electronic gift cards in a between‐subjects design. The study also takes the selling position into consideration, in addition to the buying position considered by all previous works on the uncertainty effect. The results indicate that for all types of lotteries, the bids are higher than the bids for the worst possible realization. These findings are consistent with the internality axiom and do not support the uncertainty effect.     

Reevaluation of Revaluations: A Cross-Country Examination of the Motives and Effects on Future Performance

Abstract:  This study examines the motives for asset revaluations in a sample drawn from 35 countries that permit asset revaluations. Prior studies that examined this issue concentrated on one or two countries, the UK and Australia, and showed that revaluations are related to financing needs, the capital intensity of the firm as well as issues related to political costs. The previous literature also found that revaluations were indicators of improved future performance and that performance was related to the magnitude of the revaluations. This study shows that although the conclusions drawn from the previous studies are applicable to countries that are similar to the UK and Australia, they do not hold when applied to a much larger set of countries and that the motivations for and effects of revaluation are not uniform across various country classifications.     

Behavioral Decision Making in the (Q,R) Purchasing Model: An Experimental Study

This paper presents and analyzes the results of a decision‐making experiment in inventory management under uncertainty. The experiment included 81 participants who played the role of a small car importer facing random demand as in the (Q,R) model. The results show strong evidence of learning and convergence, and the average reorder point (R) closely approaches the optimal level for maximizing profits. However, the participants' decisions are still biased by realizations of extreme values of demand and loss of potential sales. We argue that participants are affected by recency, loss aversion, and, possibly, their own risk aversion. Copyright © 2013 John Wiley & Sons, Ltd.