  The plethora of comparison shopping agents (CSAs) in today's markets enables
buyers to query more than a single CSA when shopping, and an inter-CSAs
competition naturally arises. We suggest a new approach, termed "selective
price disclosure", which improves the attractiveness of a CSA by removing some
of the prices in the outputted list. The underlying idea behind this approach
is to affect the buyer's beliefs regarding the chance of obtaining more
attractive prices. The paper presents two methods, which are suitable for
fully-rational buyers, for deciding which prices among those known to the CSA
should be disclosed. The effectiveness and efficiency of the methods are
evaluated using real data collected from five CSAs. The methods are also
evaluated with human subjects, showing that selective price disclosure can be
highly effective in this case as well, however, the disclosed subset of prices
should be extracted in a different (simplistic) manner.
