I have often purchased data from vendors (ESRI, Claritas, etc.) who package their market potential and sales estimates. All too often, I find I have to modify it if not throw it away altogether and prepare my own estimates. Their estimates are based on formulas that may work adequately in middle- or upper-income white trade areas, but do not work where there is a significant minority population, in central city neighborhoods, or most rural locations.
The latest case is a study I am working on in the south. According to the data provided, people in this trade area spend less than 20 percent of what a normal household would spend on furniture. They do not buy any shoes.
Is this some kind of comment on the south? Po' southern folk don't wear no shoes? They just sit on a tree stump whittlin' all day?
The problem I see is that many of the people who use this data do not have the education and experience needed to look at it critically. They accept it as fact. It gets included in plans and decisions are made based on it. I see as many consultants guilty of this as planners in communities.
Maybe I am just venting. Or maybe I am a bit curious to see what experiences other people have had. Was the data good? Bad? How likely are you to notice when something is going on when the data indicates otherwise?