So in the whole anti-natalism/pro-natalism conversation (which I'm mostly agnostic/undecided on, currently), my friend who is a pro-natalist, argued that the success/stability of our world economy is dependent on procreating more children each year than the previous year, so that we not only replace the numbers of the people who existed from the previous generation (and some, to account for the statistical likelihood that many won't have children or will be sterile or die young etc), but also ensure that the population keeps growing in order to produce more and more human labor to "pay back the debts" of previous generations, because all money is borrowed from somewhere else... this is all very murky to me and I wish someone could explain it better.
She is also of the view that this will inevitably lead to population collapse/societal/civilisation collapse because we live on a finite Earth with finite resources that can't keep sustaining more humans & human consumption (and are nearing critical environmental crises), but that there isn't any other option than to keep producing more children because a declining population wouldn't be able to support itself economically either. Basically the idea seems to be that economically & societally we're on a collision course for self-destruction but the only thing we can do is keep going and making increasingly more of ourselves to keep it running (however that as individuals, we should be plant-based & minimalist to reduce our impact to the environment, non-human animals and humans for as long as possible). And she is worried about the fact that fertility rates are falling & slated to reach a population peak followed by a decline in the relatively near future.
As I said I'm not sure how I feel about this view but at first glance I think that the effect of having fewer children in providing relief upon the environment and helping safeguard our future is more important than preserving the economy because destroying the actual planet and life itself seems worse than economic downturns/collapses, but I really don't know enough about economics to say for certain.
There is no law of economics stating that a generation of people has to consume more than it produces.
I mean, just as you've phrased it, if generations only consume more than they produce in an environment of finite resources, the species would only survive a finite amount of time.