Hi,
I have tried sorting this one out by looking at previous fora, the manual and the YouTube video but actually feel i have got conflicting advice. I am trying to correct for different distributions across age and am using Stata 14.1. The Stata official video at https://www.youtube.com/watch?v=lWXhGeT8u5M seems to recommend that on the "poststratification" tab under svyset, you enter a variable indicating population proportion of the reference population in "Poststratum weights" (weight1 below) and the stratum to which it refers into "Poststrata" (q10age below). Other sources seems to say that what gets entered into "Poststratum weights" is a variable which is calculated as the population percent divided by the sample percent (for each stratum; weight2 below). They are obviously quite different. i have put mine below. The latter makes more sense to me, but the video clearly says otherwise. It is also not clear to me how to create a combined poststratification weight when you do not have cell proportions - ie., if i want to have poststratification weights for age and gender but only have population proportions for age separately to gender rather than age*gender.
Thank-you,
Anne
I have tried sorting this one out by looking at previous fora, the manual and the YouTube video but actually feel i have got conflicting advice. I am trying to correct for different distributions across age and am using Stata 14.1. The Stata official video at https://www.youtube.com/watch?v=lWXhGeT8u5M seems to recommend that on the "poststratification" tab under svyset, you enter a variable indicating population proportion of the reference population in "Poststratum weights" (weight1 below) and the stratum to which it refers into "Poststrata" (q10age below). Other sources seems to say that what gets entered into "Poststratum weights" is a variable which is calculated as the population percent divided by the sample percent (for each stratum; weight2 below). They are obviously quite different. i have put mine below. The latter makes more sense to me, but the video clearly says otherwise. It is also not clear to me how to create a combined poststratification weight when you do not have cell proportions - ie., if i want to have poststratification weights for age and gender but only have population proportions for age separately to gender rather than age*gender.
| q10age | Pop N (PRData) | weight1 | Samp N | Samp % | weight2 |
| Age18-24 | 16530 | 0.1065 | 21 | 0.0243 | 4.382716049 |
| Age25-34 | 52092 | 0.3357 | 170 | 0.1965 | 1.708396947 |
| Age35-44 | 48054 | 0.3096 | 310 | 0.3584 | 0.863839286 |
| Age45-49 | 16085 | 0.1036 | 140 | 0.1618 | 0.640296663 |
| Age50-54 | 10593 | 0.0683 | 99 | 0.1145 | 0.59650655 |
| Age55-64 | 9147 | 0.0589 | 93 | 0.1075 | 0.547906977 |
| Age65+ | 2688 | 0.0173 | 32 | 0.037 | 0.467567568 |
| 155189 | 0.9999 | 865 | 1 |
Thank-you,
Anne