I guess you can slice it two ways.
1) The expected financial value of a pension. Especially assuming that the millenial in question won’t be willing to tolerate poor quality of life long enough to make it lucrative.
2) Belief that the institution backing the pension will be willing and capable of meeting their obligations in N years.
Personally, I think I’d say that the pension would be close to the value of stock options, but I’d be unwilling to tolerate the crap long enough to actually earn a useful percentage of its theoretical value.