Or what if Bob bought a filet mignon instead of a hamburger. Maybe farmers will now be (on the margin), breeding cows that produce less hamburger but more steak. This could increase the price of food that poor people eat. If Bob buys a Tesla, maybe Bob helps expand the supply of Teslas, but now buying a Corolla is slightly more expensive, because there are slightly fewer economies of scales in sedans. (This is actually happening, BTW, as Americans buy larger cars.) I also spoke of Bob taking a vacation. He spent a thousand dollars on plane tickets, which has serious deleterious environmental effects, and for the most part represents a purchase of oil, not labor services. Oil workers wages may have gone up a bit, but most of the money just went into the pocket of whoever owns the oil.
These are just some examples of possible things that could happen. Without empirical testing, we could not know what the exact impacts of any given decision are, and realistically, we do not have the resources to track the impacts of each decision through the economy.
I could be completely off here but am interested in opinions on this.
On the other hand, when you invest in a stock, you're providing liquidity to whoever held it last. That doesn't directly provide money to a company. But it has an important function: people only buy stocks when they are confident they can later sell it. If there were no buyers for stocks in the secondary market, nobody would participate in IPOs.
As far as which is better for the economy, this is beyond my knowledge. However, any normal person with any financial savvy knows that market returns are much better than deposit returns, so most of the time when such people say "save" they mean "invest in the market."
That's not actually true, banks effectively create money when making a loan, and the only constraints on this are the interest rate set by the central bank, which affects both demand for credit and the cost of providing it, and liquidity requirements set by legislation.
https://www.bankofengland.co.uk/-/media/boe/files/quarterly-...
And, if I understand the arguments, that's confirmed by Piketty's r (return on capital) > g (economic growth rate). My concern is that more money is getting tied up in chasing financial assets than in the real economy (houses, hamburgers, cows, etc.) If you have financial assets, that's good. If you don't, that's bad. Most people don't have financial assets. Sooner or later something's going to correct that trend. It'd be better to find a non-violent solution.