Preface: About the data

Where did we look for data?

Due to the scarcity of centralised data on immigration detention, we looked for data that exists under multiple government departments. Furthermore, the limited data on detention makes comparative data, such as with prison institutions, increasingly relevant.

We have looked at thousands of pages of literature and reports, and hundreds of data sources, including- but not limited to:

  • Immigration Department Annual Reports
  • Immigration Department Enforcement Stats webpage
  • Correctional Services Department Stats webpage
  • Hong Kong Government submissions to United Nations bodies
  • LegCo press releases
  • Security Bureau Replies to Finance Committee
  • Hong Kong Government Data Portal
  • Census and Statistics Department website
  • Hong Kong Police Force website
  • Access to information requests (by others)
  • Access to information requests (filed by this project)
  • and more

What are the difficulties in finding data?

Thus, the difficulty of finding data on detainee population is in part due to the fact that detainees may be scattered across multiple institutions under the authority of multiple departments.

Another difficulty is that datasets that cover different time periods might not use the same measurement; this makes merging datasets to get a larger time period not possible.

Measurements and units

Data measures that have been used in the datasets we encountered include:

  • yearly admittances,
  • average daily population, and
  • a snapshot of the population at a given date (ex. end of the month, end of the year)

Yearly admittances can illuminate the scale of turnover in a facility while average daily population could be useful to understand which years a facility is closer to capacity. However since average daily population would never exceed the capacity of the facility, a broader comparison between facilities may remain limited.

Vocabulary List

Commonly Used Abbreviations

CIC – Castle Peak Bay Immigration Centre

CIU – Complaints Investigation Unit (of the Correctional Services Department)

CSD – Correctional Services Department

HKPF – Hong Kong Police Force

ImmD – Immigration Department

MTKDC – Ma Tau Kok Detention Centre

NKCI – Nei Kwu Correctional Institution

TTG / TTGCI – Tai Tam Gap Correctional Institution

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