Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-06T06:18:55.336Z Has data issue: false hasContentIssue false

Why do these quite different best-choice problems have the same solutions?

Published online by Cambridge University Press:  01 July 2016

Stephen M. Samuels*
Affiliation:
Purdue University
*
Postal address: Department of Statistics, Mathematical Sciences Building, 150 North University Street, West Lafayette, IN 47907-2067, USA. Email address: [email protected]

Abstract

The full-information best-choice problem, as posed by Gilbert and Mosteller in 1966, asks us to find a stopping rule which maximizes the probability of selecting the largest of a sequence of n i.i.d. standard uniform random variables. Porosiński, in 1987, replaced a fixed n by a random N, uniform on {1,2,…,n} and independent of the observations. A partial-information problem, imbedded in a 1980 paper of Petruccelli, keeps n fixed but allows us to observe only the sequence of ranges (max - min), as well as whether or not the current observation is largest so far. Recently, Porosiński compared the solutions to his and Petruccelli's problems and found that the two problems have identical optimal rules as well as risks that are asymptotically equal. His discovery prompts the question: why? This paper gives a good explanation of the equivalence of the optimal rules. But even under the lens of a planar Poisson process model, it leaves the equivalence of the asymptotic risks as somewhat of a mystery. Meanwhile, two other problems have been shown to have the same limiting risks: the full-information problem with the (suboptimal) Porosiński-Petruccelli stopping rule, and the full-information ‘duration of holding the best’ problem of Ferguson, Hardwick and Tamaki, which turns out to be nothing but the Porosiński problem in disguise.

Type
General Applied Probability
Copyright
Copyright © Applied Probability Trust 2004 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Berezovsky, B. A. and Gnedin, A. V. (1984). The Problem of Best Choice. Nauka, Moscow (in Russian).Google Scholar
Campbell, G. and Samuels, S. M. (1981). Choosing the best of the current crop. Adv. Appl. Prob. 13, 510532.Google Scholar
Ferguson, T. S., Hardwick, J. P. and Tamaki, M. (1992). Maximizing the duration of owning a relatively best object. In Strategies for Sequential Search and Selection in Real Time (Contemp. Math. 125), American Mathematical Society, Providence, RI, pp. 3757.Google Scholar
Gilbert, J. P. and Mosteller, F. (1966). Recognizing the maximum of a sequence. J. Amer. Statist. Assoc. 61, 3573.Google Scholar
Gnedin, A. V. (1996). On the full information best choice problem. J. Appl. Prob. 33, 678687.Google Scholar
Gnedin, A. V. (2004). Best choice from the planar Poisson process. To appear in Stoch. Process. Appl. CrossRefGoogle Scholar
Petruccelli, J. D. (1978). Some best choice problems with partial information. Doctoral Thesis, Purdue University.Google Scholar
Petruccelli, J. D. (1980). On a best-choice problem with partial information. Ann. Statist. 8, 11711174.Google Scholar
Porosiński, Z., (1987). The full-information best choice problem with a random number of observations. Stoch. Process. Appl. 24, 293307.Google Scholar
Porosiński, Z., (2002). On best choice problems having similar solutions. Statist. Prob. Lett. 56, 321327.Google Scholar
Presman, E. L. and Sonin, I. M. (1972). The best choice problem for a random number of objects. Theory Prob. Appl. 17, 657668.CrossRefGoogle Scholar
Samuels, S. M. (1982). Exact solutions for the full information best choice problem. Mimeo Ser. 82-17, Department of Statistics, Purdue University.Google Scholar
Samuels, S. M. (1991). Secretary problems. In Handbook of Sequential Analysis, eds Ghosh, B. K. and Sen, P. K., Marcel Dekker, New York, pp. 381405.Google Scholar