1. It depends what you mean by turn on the printing presses. In...

1. It depends what you mean by turn on the printing presses. In fact the printing presses have been on and money has been freely available for the last five years. It is this easy money that effectively fuleeled the last stages of the stock market bubble.
Because of concerns about the Y2K bug the Fed flooded the banking system with cash in 1999 fueling the stockmarket bubble. If the US has a serious recession this is another policy option, albeit only likely to be used as a last resort.

2. Government spending and lowering interest rates to zero do not have the desired Keynesian `effect in a deflationary situation. The Japanese have had NEGATIVE interest rates for much of the past ten years, and have built one bridge after another to nowhere - and all it has done has kept them one step ahead of depression.
You are correct that -ve real interest rates and fiscal policy have failed in Japan. That is why the rest of the world recommends that Japan should set an inflation target and acheive it through an increase in the money supply. From the Economist: "The Bank of Japan has promised not to raise rates until prices start to rise again. It has also promised to increase the supply of money. What it has not done is explicitly to link the two, by promising to print money until it creates inflation. Yet this is what the Japanese government and some economists have been urging it to do: print lots of money, force the yen lower, and get people to start believing that prices must soon start to rise. "



3. The US would have to sack every single economist it has, and fight the IMF as well, before it engaged in hyperinflationary money printing. EVERY economist is weaned on an unreasoning fear of inflation, even though we havent had any for a decade. They can point to Germany and eastern Europe in the 1920s, and Latin America since then, to show what can happen. They will NEVER debase the currency in this way.
Economists say we should aim for price stability, generally defined as inflation of 0-2%. Both deflation and inflation are bad. If the economy is stuck in deflation then policies to increase inflation would not only be acceptable to economists, they would be strongly advocating these policies. Economists are well versed in the history of the great depression and the crazy economic policies that contributed to it. ie The naive belief that the govt had to keep a neutral fiscal policy, and the failure of the govt to act as the lender of last resort in a liquidity crisis. These mistakes need not happen again.