Depends upon your parameter definition of "long term"... but in general... inflation, government deficit spending, currency destruction and government greed/power lust. All coordinate to move stock prices higher in the long run.
Investors' aggregated perception of potential growth and change in value. Once stocks have moved to those levels, the perceptions must change before stocks will begin a new advance.
If no earnings at some point the stock falls. But investors look at potential of earnings. Google didn't have earnings for a while but potential was high. But I think at the end earnings is what counts most. Talking about long-term only.
Well I meant individual stock. Where do we find out what the earnings potential is or what people think about the future of the company? I looking at the quarterly summeries or the sec-10k papers but I couldn't find anything. But I think the economy also has an effect on an individual stock.