How to calculate the population of a specific year (for example 1974) with decennial census data of 1970 and 1980.


#1

With decennial census data( population, for example 1970 and 1980) i would like to calculate the population of specific years (for example 1974). The dataset is in a panel structure where in the columns are the decennial census data and in the rows the cities (nhgiscode) and the years i would like to calculate the population for in a new variable. Is there a specific command (STATA preferred) i can use or some other possibilities?

As you can see in the image the population of ´70 and ´80 is given and i want to fill the variable popnew.

Thank you for your help!

kind regards

Nicolai

questionImage1955097-09122014-full.jpg


#2

Dear Nicolai,

The most straightforward way to create intercensal estimates is thru linear interpolation. You would subtract the pop70 value from pop80 (40165-20411 = 19574) in your example. Then I would divide the difference by 9 (19574 / 9 = 2174.9). I would then set the 1971 value equal to the pop70 + 2174.9. Finally, loop through all the years, adding 2174.9 to each prior year.

I don’t know the exact stata commands to execute this, but that is the basi algorithm.