This study seems fishy. It is based largely on Social Security which is presented to most people as a mandatory retirement program. The amount one receives from social security is affected by the amount one pays in.
For a study to be valid, it would need to compare the amount that people pay into welfare programs through their whole lives and compare that to the amount they receive.
I don't think including SS is unwarranted. In practice it amounts to transferring resources from the young to the old. That is definitely a form of welfare, even if the government also promises to transfer resources to the now-young in the future from the future young.
Interestingly, we have immigrants paying into SS, but collecting from it at lower rates.