There is certainly something cultural going on—at least in the US, I notice this. Older generations will look at you with puzzled expressions if you ask them about what made them decide to have children and why they thought it was worth it at the time. Having children simply wasn't a question for people that were born before a certain year.
Analyzing the tradeoffs of having children does not lead to some profound realization—mostly people recognize that it would take a lot of their time, and that sounds like that might make them less happy. But we also know that humans are not really very good at judging what would make them happy.
We also know that as you say, economic forces have normalized a situation where it's difficult for two people to find the time to justify the value of child-rearing. But I find it hard to see how we reverse this trend if the only discussion is economic—people don't have more children in Scandinavia even though the economic burden is lower.
You mean, the generation before them were financially inevitably fucked if they didn't have children. For our parent's generation it was more-or-less neutral and for this generation it's a strong financial disincentive. You have enough (barely, but still), right into old age, if you don't have children. In fact it's easier without children. Simple as that.
As for a solution short of canceling pension plans? That would do it, of course, but ... of course this is exactly what current governments in EU, US, Japan, ... are effectively doing: canceling pension plans. They can either cancel pensions in the future ... or they can choose to spend much less now. So of course they are really reducing pensions (from already insufficient levels to basically nothing...) That won't help the current generation choose children, although that may turn out to be the smart play. The trouble is humans largely don't learn rationally, we learn from example. So we first need to see a large number of Americans and Europeans (and ...) fall into destitution after 65, and see the few that did have many children get rescued by their children from that fate, only then will we choose to have children again.
I guess this is how natural selection stabilizes the human population.
This has happened before and it will happen again. (seriously, human birth rates change in "waves")
Analyzing the tradeoffs of having children does not lead to some profound realization—mostly people recognize that it would take a lot of their time, and that sounds like that might make them less happy. But we also know that humans are not really very good at judging what would make them happy.
We also know that as you say, economic forces have normalized a situation where it's difficult for two people to find the time to justify the value of child-rearing. But I find it hard to see how we reverse this trend if the only discussion is economic—people don't have more children in Scandinavia even though the economic burden is lower.