A common concept in site location research is that of "daytime population", which attempts to distinguish between the residential population (those who live in an area) and those who are present during the day. The daytime population most simply put is:
Total resident population + Total workers working in area - Total workers living in area
The problem is that for small areas it is difficult to obtain good estimates of how many of the daytime workers also live in the area, especially when it is dynamically estimated (e.g. for a ten mile radius). In practice, it is presumed that a good surrogate for this is:
Total Employment + Population Not in Labor Force + Population Unemployed
In AGS variable terms, this is simply BUSCYEST + LBFCYNLF + LBFCYUNEMP. Population Not in the Labor Force includes persons who are not working and not attempting to find work.
In our view, the concept of daytime population, while perhaps of marginal curiosity, is of little value to most analytical applications. In essence, the problem is that from a demand perspective -- the constituent groups have little in common. The daytime population consists of:
* employed persons
* unemployed persons
* children under the age of 18
* adult students
* stay-at-home parents
As a demand measure, counting each of these as equivalent (which such a computation does) makes little sense. That said, while AGS is not generally in favor of using this measure, it can nevertheless be computed within Snapsite.