1. A method for anonymizing data collected in a data collection system, said method comprising: collecting a first identifier, said first identifier uniquely identifying a first one of a plurality of households; determining a second identifier, said second identifier being descriptive of a geographic location associated with said first household; concatenating said first and second identifiers; converting digits of said concatenated identifiers to a first converted format yielding a first converted string of digits; dividing said first converted string of digits into a plurality of first and second alternating segments; adjusting each of said plurality of first and second alternating segments by: adding a first fixed value to said plurality of first segments; and subtracting a second fixed value from said plurality of second segments; converting said adjusted plurality of segments to a second converted format; performing a cryptographic hash of said second converted plurality of segments to produce one or more results; and storing said one or more results on a computer readable storage apparatus.