In IPUMS-USA, how do I apply the variable SLWT?
SLWT is a special weight that is only applicable to the 1940 and 1950 samples. The application of weights depends upon the statistical package being used, so I recommend looking into the methods for your specific statistical software.
The IPUMS-USA website does have access to an online data analysis tool, and to apply SLWT using this tool you simply need to select it in the “Weight:” drop down menu.
I hope this helps.