Molson Hart

The whole point of lower interest rates is to spur investment, so we can cure a lack of investment in economic downturns. Same idea with injecting liquidity into the system, i.e. printing money. What would happen if we spent an equivalent amount of money on an advertising

campaign that encouraged people to invest or become entrepreneurs?

I doubt it would work. And it would be an insanely huge sum of money to spend on advertising that even if it did work, you'd quickly run into diminishing gains. The most direct way to spur entrepreneurship is to provide subsidies (grants, tax breaks, etc.).