Way WAY too many "studies" are done this way - the famous "50% can't afford a $500 unexpected expense" study for example is a survey asking people if they could spend $500 without worry.
It's cheaper, but it's not better. True investigations watch results over time and compare actual items (that still have to be determined to be significant).
It's cheaper, but it's not better. True investigations watch results over time and compare actual items (that still have to be determined to be significant).