(i) it's a very interesting point that you put forth. Yes, robots will compensate for the _working population_ ; However, I think the OP wants to direct the att

(i) it's a very interesting point that you put forth. Yes, robots will compensate for the _working population_ ; However, I think the OP wants to direct the attention towards the economic impact of a changing demographic. Robots won't earn and [ borrow and ] spend. Consumption, Consumerism and the access to Capital is the reason world GDP has multiplied manifold in the last century and why it continues to grow. A shift in demographic has a massive impact on that.