I think it's hard to view that way because of the way the work and pressures come. I have two kids a couple of years apart. The youngest one is still at an age

I think it's hard to view that way because of the way the work and pressures come. I have two kids a couple of years apart. The youngest one is still at an age where sleeping at night is an on-off business but the oldest one is now fine. With twins you wouldn't get that as they're both at the bad sleeping stage at the same period and that's something which re-enforces - two non-sleeping children at the same time is way worse than two non-sleeping children sequentially as there will be a period where you'll almost never get a good night. Similarly my older child can now feed herself which means that meal times with the two of them are easier than they would be if both needed feeding. Over all time, it might average out to close to the same amount of work per child (in later life they might entertain each other a bit more being the same age), but there are two or three years at the beginning where you're going to be severely punished. Also financially there's no hand me downs with twins - they both want / need stuff at the same time.