Like the man said, with statistics, you can prove anything, even the opposite.
Before citing the stats from various studies, study the studies. Find out what they are really saying.
As for the fellow above who said, "As a rule, the more a person has to work for a thing, or the greater the sacrifice a person must make to attain a thing, the more valuable that thing will be to the person," that is impression that refers to, not fact. Just because someone believes in something doesn't make it true - and doesn't make it as effective as they may report.