What are population denominators?
We use population denominators for a large portion of the data we hold in Local Insight. This refers to indicators that are displayed on maps and reports as rates, calculated using the population as a denominator.
We use population denominators to easily compare data across areas.
If area A has 150 Unemployment Benefit claimants and area B has 250, we may interpret area B to have a higher instance. However, these areas both have different sized populations and compare differently if this is taken into account. If we use a population denominator, in this case, we would use the working age population (aged 16-64) we could interpret this more accurately. If area A has an estimated working age population of 2000 and area B has 4500, the Unemployment benefit claimant rate for area A is 7.5%, whereas area B is 5.6%, thus area A has a higher proportion of Unemployment Benefit claimants with respect to its population size.
Rate calculated as = (Unemployment benefit claimants (Jobseekers Allowance and out of work Universal Credit claimants))/(Population aged 16-64)*100
We create rates for different scales of population size per 100, 1000, 10,000, or 100,000 people depending on the nature of the data we are handling. For example, if we are using data that has relatively low counts per area, e.g. crime incidence we would use a rate per 1000 of the population to make the data more meaningful.
Mid-year population estimates
To create the population denominators, we use the annually published Mid-year population estimates provided by the Office for National Statistics. These are also available on Local Insight.