Hierarchy of zones and re-estimation

• At supra-district scale: CIDS have constructed sets of ‘approximately consistent zones’ from the initial set of 459 GB districts in 1991 and 408 GB districts in 2001:

• - ‘district’ geography (417 zones)

• - ‘intermediate’ geography (219 zones)

• - ‘100 zone’ geography (100 zones)

• - ‘city region’ geography (47 zones)

• - ‘Government Office Regions’ (12 zones)

• At sub-district scale: CIDS also re-estimated various sets of sub-district flows from 1981 and 1991 Censuses for 2001 boundaries (Boyle and Feng, 2003)

Notes:

The response from CIDS to the latter problem has been to construct a 5 tier hierarchy of zones from the initial set of 459 districts in 1991 and 426 districts in 2001:

- ‘district’ geography (417 zones)

- ‘intermediate’ geography (219 zones)

- ‘100 zone’ geography (100 zones)

- ‘city region’ geography (47 zones)

- ‘Government Office Regions’ (12 zones)

Data for these zone systems at supra-district scales are approximately consistent between 1991 and 2001

CIDS also re-estimated various sets of sub-district flows from 1981 and 1991 Censuses for 2001 boundaries (see Boyle and Feng, 2003)