[berberous]

Sure, but that's probably going to unfairly impact the poor. Imagine a family of poor immigrants, where the father worked very hard and saved and left some asset to his non-rich children...you want to punish the children when the father dies suddenly and the children have no idea where to find cost basis information? There are pros and cons to any policy.

[compsciphd]

you can also limit step up cost basis, similar to how the "estate tax" is limited (and is high enough that even "normal" rich people aren't event impacted by it. But I'd limit the step up stricter than that. imagine the step up would be limited to 1-2mil of stepped up assets. poor people would still be able to benefit, nominally middle class/well to do upper middle class would also mostly benefit, but the rich would find the benefit effectively go to zero for them as their assets rise.