Archive for undercount

surveying homelessness

Posted in Books, pictures, Statistics with tags , , , , , , , , , , , on February 26, 2023 by xi'an

A recent NYT article, entitled “582,462 and Counting“, is describing how the USA Federal Administation is running a yearly survey of homeless people. By sending agents and volunteers in the streets and shelters to get an idea of the magnitude of the problem. The figure of 582,462 was the one produced by HUD (the US Department of Housing and Urban Development) for 2022. In the methodological instructions related to this survey,  I could not find any mention of an advanced statistical technique such as capture-recapture. Despite a possible call to statistical software

The next step is to enter data from the survey into a computer program, such as SPSS, SAS, Excel, or the CoCs’ HMIS.

And both undercount and overcount are not formally addressed

CoCs must ensure that during the PIT count homeless persons are only counted once. It is critical that the counting methods be coordinated to ensure that there is no double-counting. Therefore, CoCs must also collect sufficient information to be able to deduplicate the PIT count (i.e. ensure that the same homeless person was not counted more than once.

(where CoC stands for Continuum of Care and PiT Point-in-Time). (I remember discussing homeless surveys in the 1990’s with researchers from INED, albeit they had already launched their survey and would thus be unable to “recapture” interviewees.)

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