I'm currently working on a project looking at the relationship between income and place of residence (by PUMA/County) using the 1-Yr ACS PUMS. I want to use covariate balance/matching to show that living in a certain PUMA/county affects one's income. I was wondering if I have to use the person weight (PWGT) before I do the matching/balancing process. Do I have to use the weight (PWGT) at all for causal inference analysis (propensity score matching, regression discontinuity)? I have not used PUMS for causal inference analysis before and I would like to hear your feedback. Thank you so much for your time!