Goal
I would like to figure out how to weight aggregated survey data to try to 'fix' the fact that a survey is not representative at the subnational level.
Background
I am attempting to aggregate survey data to the subnational level (Admin 1). I have data from a survey which is representative at the national level, but is not representative at the subnational level. When I aggregate data, some regions are represented by several hundred observations, whereas other regions are represented by only a dozen observations.
I would like to weight these aggregations so that each region is not over (or under) represented. I wouldn't want a region with 12 responses to be measured equally with a region with 140 responses.
My Solution
As far as I can figure, the best way to do this is to standardize the subnational means to the larger national mean, since I know that the survey is representative at the national level.
Here is what I came up with:
- I can acquire the aggregated mean of a given variable at the region-level ($\mu_{region}$)
- I can acquire the number of data points for each given variable at the region-level ($N_{region}$
- I can acquire the number of data points for each given variable at the country-level ($N_{country}$)
I would then weight each given aggregated mean by multiplying it against the ratio of the number of region data points to the number of country data points.
$$ Weighted.Variable = \mu_{region} * \frac{N_{region}}{N_{country}} $$
Question
Is this approach statistically appropriate for correcting for a lack of subnational representation?
I need a mind (or minds) greater than my own to figure out whether this is an appropriate transformation to apply to my data. If it is not, where should I look to solve this problem?
Thank you all so much for your help!