Instead of injecting money top-down through the Federal Reserve and large banks, they could inject it bottom-up in selected industries. Invest $1 trillion in biotech. Some will succeed and produce amazing advances. Most will fail, but they'll still drive employment, education, services, etc. targeting that industry, driving down the cost of inputs to the biotech sector for decades.

Of course, this can be done not completely blindly, by investing 10 to 1 with existing investors, or providing a guarantee to return 50% of lost capital, or having milestones companies need to hit, or have experts in the field provide "votes" toward getting higher levels of funding after examining their progress so far.