Robust sequential search

• 成果类型: Article
• 署名作者: Schlag, Karl H.; Zapechelnyuk, Andriy
• 署名单位: University of Vienna; University of St Andrews
• 刊物名称: THEORETICAL ECONOMICS
• ISSN/ISSBN: 1933-6837
• DOI: 10.3982/TE3994
• 发表日期: 2021-11-01
• 页码: 1431-1470
• 关键词: Sequential search; search without priors; Robustness; dynamic consistency; competitive ratio; C44; D81; D83

摘要

We study sequential search without priors. Our interest lies in decision rules that are close to being optimal under each prior and after each history. We call these rules robust. The search literature employs optimal rules based on cutoff strategies, and these rules are not robust. We derive robust rules and show that their performance exceeds 1/2 of the optimum against binary independent and identically distributed (i.i.d.) environments and 1/4 of the optimum against all i.i.d. environments. This performance improves substantially with the outside option value; for instance, it exceeds 2/3 of the optimum if the outside option exceeds 1/6 of the highest possible alternative.