Missing inctot in 1950 census

The availablility of the inctot variable says that it’s available for 1950. However, after I downloaded the data I found that only 20% of the 1950 sample have non-missing inctot. Why are there so many missings? Is this how the data are, or is it due to some technical problems? Does this mean that I can’t do any analysis using the 1950 income data?

Proposed Answer:

The reason you are seeing so many missing values for INCTOT for 1950 is because the Question Universe for INCTOT in 1950 was restricted to Sample Line individuals. To generate accurate estimates from Sample Line data you will need to use the special weight variable SLWT.

I hope this helps.