The Myopic Property in Decision Models

2019 ◽  
Vol 16 (2) ◽  
pp. 128-141 ◽  
Author(s):  
Manel Baucells ◽  
Rakesh K. Sarin

We examine conditions under which decisions made in isolation provide an optimal strategy for the multiperiod problem. We focus on investment decisions with constant returns to scale. We first consider the framework of subjective expected utility. Under minimal assumptions (i.e., without assuming utility is concave), we prove that only log utility is myopically optimal when returns are serially correlated. When returns are serially independent, we generalize Mossin’s result [Mossin J (1968) Optimal multiperiod portfolio policies. J. Bus. 41(2):215–229.] that only log and power, including linear and convex, possess the myopic property. Finally, we extend the inquiry when probabilities are uncertain and the decision maker uses the recursive smooth model of ambiguity to identify an optimal strategy. We show that with serial correlation, preferences including ambiguity concerns cannot be myopic and optimal. Without correlation, we identify the exact pairs of utility and ambiguity functions that permit myopic decision rules.

2006 ◽  
Vol 6 (1) ◽  
pp. 1-31
Author(s):  
Lawrence Uren

This paper examines the allocation of heterogeneous workers across sectors of an economy in which workers are able to direct their search towards particular firms. We find that search frictions, in addition to causing unemployment, may result in an inefficient allocation of labor. This result arises because of the interaction between the investment decisions of firms and the search decisions of workers. Despite constant returns to scale in both the matching and production functions, this interaction can generate multiple equilibria. The existence of multiple equilibria is shown to depend crucially on the direction of comparative advantage.


ILR Review ◽  
1992 ◽  
Vol 45 (4) ◽  
pp. 711-723
Author(s):  
Craig A. Olson ◽  
Gregory G. Dell'omo ◽  
Paul Jarley

Recent studies have investigated arbitrator decision rules in both experimental and field settings. The authors of this paper evaluate the external validity of experimental studies by comparing the decisions made in an experiment with those made in actual cases by the same arbitrators. The results show that when the single-issue decisions made in the experiment are compared with the multi-issue decisions made in many field cases, the arbitrators' decision models in the two settings (as indicated by the weights they attached to various facts of the case and their level of uncertainty about which offer to choose) appear to differ; but when the experimental data are compared to the decisions in the sample of field cases in which the wage was the only issue, the decision models are substantially the same.


Author(s):  
Carlos Alós-Ferrer ◽  
Johannes Buckenmaier ◽  
Georg Kirchsteiger

AbstractWhen alternative market institutions are available, traders have to decide both where and how much to trade. We conducted an experiment where traders decided first whether to trade in an (efficient) double-auction institution or in a posted-offers one (favoring sellers), and second how much to trade. When sellers face decreasing returns to scale (increasing production costs), fast coordination on the double-auction occurs, with the posted-offers institution becoming inactive. In contrast, under constant returns to scale, both institutions remain active and coordination is slower. The reason is that sellers trade off higher efficiency in a market with dwindling profits for biased-up profits in a market with vanishing customers. Hence, efficiency alone might not be sufficient to guarantee coordination on a single market institution if the surplus distribution is asymmetric. Trading behavior approaches equilibrium predictions (market clearing) within each institution, but switching behavior across institutions is explained by simple rules of thumb, with buyers chasing low prices and sellers considering both prices and trader ratios.


2019 ◽  
Author(s):  
Amelia R. Hunt ◽  
Warren James ◽  
Josephine Reuther ◽  
Melissa Spilioti ◽  
Eleanor Mackay ◽  
...  

Here we report persistent choice variability in the presence of a simple decision rule. Two analogous choice problems are presented, both of which involve making decisions about how to prioritize goals. In one version, participants choose a place to stand to throw a beanbag into one of two hoops. In the other, they must choose a place to fixate to detect a target that could appear in one of two boxes. In both cases, participants do not know which of the locations will be the target when they make their choice. The optimal solution to both problems follows the same, simple logic: when targets are close together, standing at/fixating the midpoint is the best choice. When the targets are far apart, accuracy from the midpoint falls, and standing/fixating close to one potential target achieves better accuracy. People do not follow, or even approach, this optimal strategy, despite substantial potential benefits for performance. Two interventions were introduced to try and shift participants from sub-optimal, variable responses to following a fixed, rational rule. First, we put participants into circumstances in which the solution was obvious. After participants correctly solved the problem there, we immediately presented the slightly-less-obvious context. Second, we guided participants to make choices that followed an optimal strategy, and then removed the guidance and let them freely choose. Following both of these interventions, participants immediately returned to a variable, sub-optimal pattern of responding. The results show that while constructing and implementing rational decision rules is possible, making variable responses to choice problems is a strong and persistent default mode. Borrowing concepts from classic animal learning studies, we suggest this default may persist because choice variability can provide opportunities for reinforcement learning.


Author(s):  
Georgi Kiranchev

The article examines the behavior of students and employers as a bimatrix game. With the tools of game theory, it is generally proven that the optimal strategy for employers is to pay low wages, and for students – not to study or to study too little. These two strategies form the Nash’s equilibrium in pure strategies. No specific numbers were used in the evidence, but only plausible assumptions about the relationships between the used parameters. This generalizes the conclusions made in the general case of higher education. Such a study of the question using game theory has not been done yet.


Author(s):  
Tiziana Caliman ◽  
Paolo Nardi

The aim of this work is to introduce a first analysis concerning the relevance that ownership and financial structure, but also market dimension and business portfolios, have on the technical efficiency of Italian water utilities. Even though scholars have provided information on the influence of some dimensional or geographical variables, mono-utility character or ownership on efficiency, no paper, to the best of our knowledge, has ever considered the presence of all these hedonic variables as efficiency shifters or drivers. Antonioli and Filippini (2001) have not included ownership; Benvenuti and Gennari (2008) have included ownership and multi-utility strategy, but excluded the geographical dimension; Fabbri and Fraquelli (2000) have not included geographical location, business strategy or ownership; furthermore, most analyses of the Italian water sector have focused on the ATO level (investments, labour costs) and not on utility performances. We have estimated four heteroskedastic stochastic production frontiers: two different parametric models, where the hedonic dummy mono is either in the model as an additional variable or it is used to parameterize the variance of the inefficiency term; two competitive statistical formulations have also been introduced to specify the inefficiency component distribution, that is, the half normal and the exponential distributions. The most important findings of this paper can be summarized as follows. The labour, capital and other input elasticities are always highly significant, positive and quite stable in all the performed models, as expected for a well-behaved production function. The main results show that the mono-business strategy is not efficient; at the same time, operating water and sewerage together implies higher efficiency than water- only management. Theoretically, the population density can have an ambiguous effect on efficiency: on one hand, it could be more expensive to serve dispersed customers, but, on the other, it could generate congestion problems. It could be argued that the second effect prevails, therefore a higher density is accompanied by a higher inef- ficiency. The analysis points out that the variance of the idiosyncratic term is a function of the size of the firm, which is measured as the number of connected properties; the null hypothesis, that the firms use a constant returns-to-scale technology, has also been rejected. Considering the 1994 reform, it is possible to state that the integration of water and sewerage has substantially been positive; at the same time, the economies of scale and the ambiguity of density justify the division into provincial basins. The role of the private sector in the water industry, in agreement with previous literature, has neither a positive nor a negative impact on efficiency and ownership is simply not influent [obviously the quality of service should be considered, although the same indifference seems to emerge (Dore et al., 2001)]. Southern Italy suffers from a higher degree of inefficiency (also recently confirmed by Svimez, 2009), and this is probably the most important issue that has to be dealt with, because of the risks of drought and watering bans in those Regions during summer.


Author(s):  
Yves Balasko

This chapter analyzes an equilibrium model where privately owned firms feature either smooth decreasing or constant returns to scale. Profit of the constant returns to scale firms being equal to zero at equilibrium, the equilibrium of the model does not depend on the ownership structure of these firms. In addition, the convex conical production sets of these firms sum up into a convex cone. It is as if the production sector operating under constant returns consists of a unique firm. The general equilibrium model with decreasing and constant returns to scale firms is essentially the same model as the one considered in Chapter 10 with the addition of a unique firm operating under constant returns to scale. Nevertheless, this addition is enough to hamstring the approach of the preceding chapters based on the concept of price system that equates aggregate supply and demand. The solution is to add to that price system the activity of the constant returns to scale firm.


2020 ◽  
Vol 6 (02) ◽  
pp. 60-72
Author(s):  
Kompalli Sasi Kumar

The study examined the exposure and efficiency of select public and private sector banks towards off balance sheet items by applying Data Envelopment Analysis (DEA) on the key financial performance ratios of banks. The study covered a period of 5 years ranging from 2013 to 2017 and conducted a year wise analysis. The study selected 20 different type of variables (financial variables) for building Input –Output Model to test DEA for examining efficiency. These variables are acting as proxy variables for indicating the effect of Off balance sheet exposures on the financial health of the business. These variables are extracted from the financial statements of respective banks on a year on year basis and required adjustments are done. The study investigated the Off balance sheet exposures in the areas of Foreign Exchange Transactions, Guarantees, Acceptance and Endorsements etc., The proxy variables, so identified for the study are employed for understanding various efficiencies of banks like scale efficiencies involve Constant Returns to Scale (CRS), Variable Returns to Scale (VRS) and average efficiencies like Technical Efficiency (TE), Cost Efficiency (CE), Allocative Efficiency (AE). The study find out that throughout the study period, the select banks exhibited constant returns to scale, except CUB and AXIS Bank in the first year of study (2013) displayed increasing returns to scale due to heavy exposures. In the category of efficiency parameters, AXIS Bank and CUB are displaying lower efficiencies in the segment of private sector banks and Andhra Bank and OBC exhibiting lower efficiencies in the segment of public sector banks. Here lower efficiencies with references to cost savings aspects and output generation, this may be due to their scale of operations in the industry. The study concluded that large banks are exhibiting highest efficiencies than compared to small banks operating in the industry. This is definitely an area for further research to the industry and researchers to examine the direct effect of Off balance sheet transactions (IFRS amendments in this direction only), so that credit risk can be reduced considerably in the business. So that business houses can take up calculated risk in the international markets.


2003 ◽  
Vol 15 (1) ◽  
pp. 145-160 ◽  
Author(s):  
John Christensen ◽  
Joel S. Demski

We study a setting in which a firm faces commercial and cost-reimbursed products, and, following Rogerson (1992), examine the factor choice distortions that are induced by the cost-based reimbursement arrangement. The firm's technology is separable, which allows us to rationalize fully an ABC procedure (given constant returns to scale) and also allows us to document whether the distortions occur in the direct or indirect subcost functions. The location and magnitude of the distortions depend on the precise costing procedure, but the preference for an ABC versus traditional procedure is far more subtle. Absent constant returns, any (linear) accounting procedure invites factor distortions because of the cost-reimbursement feedback, but the economic impact of these distortions depends on the technology, the relative prices, and the costing procedure.


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