We introduce a simple new model of sequential search among finitely many options that fits many economic applications. Each payoff is the sum of a random “known factor” and a “hidden factor”, learned at cost. Weitzman (1979) solved the ex post Pandora's box problem, given known factors....

We explore costly sequential search among finitely many risky options, and an outside option. Payoffs are the sum of a known and hidden random factor.(a) We resolve a long open question about how riskier payoffs impact search duration: expected search time is higher for more dispersed...

When is the weighted sum of quasi-concave functions quasi-concave? We answer this, extending an analogous preservation of the single-crossing property in QS: Quah and Strulovici (2012). Our approach develops a general preservation of n-crossing properties, applying the variation diminishing...