Consultation regarding the redraw of Data Zones

4. Population Change

Why Data Zones need to be redrawn

4.1. When Data Zones were first introduced, one of the main aims was to produce a static and stable geography. Maintaining the existing boundaries would be consistent with the original stated aims of Data Zones and would ensure that there are no discontinuities in any time series of statistics presented on Data Zones. The down side of this is that, where there has been significant population change, statistics presented at Data Zone level may not be as relevant as they could be.

4.2. The disadvantage of leaving Data Zone boundaries unchanged is that, where Data Zone populations have shrunk considerably, there may be disclosure issues with the statistics presented in these areas. This may mean that data might have to be withheld or rounded to prevent disclosive information from being released. In addition, where the population in an area has grown, the Data Zone may not represent a neighbourhood or small community. It also means in some cases that postcodes and Census Output Areas (COAs) need to be assigned to Data Zones on a best-fit basis, leading to inaccurately classified postcodes and COAs.