Supply would increase; demand would decrease; the price would decrease. Things get stickier when you start pondering how it will impact inflation.
Supply of labor decreases, driving up costs, driving inflation? Consumer spending decreases, lowering cost, reducing inflation? All things being equal changing a population should not change per-capita GDP (figured without the cryo-sleep people.) The sleeper's capital is dead money - not exerting any outside influence on resource allocation assuming the investment goals of their capital funds are sufficiently general to maintain a risk-adjusted rate of return.
By what mechanisms would we expect it to influence interest rates, and in what direction? Some suggestions:
Future-bound investors favouring lower-risk long-term investment strategies. I assume this would stratify interest rates, so high-risk borrowing becomes more expensive and low-risk borrowing becomes less so, likely resulting in an overall decrease in real interest rates.
Removal of high-ROI human capital from the workforce, cf. the original comic. Presumed increase in interest rates as investment becomes a less attractive prospect.
Reduction in investment capital from people in cryo. Presumed increase in interest rates as the availability of investment funds decreases.
The biggest game-changer would be if the cost of cryo was less than the cost of living. If it's cheaper for someone to be on ice than walking around, that introduces a lot of very strange and interesting options.
Any additions/disagreements?
If there is mortality, the total amount of time alive is constant, and with it the cost, so the cost of living is irrelevant.
If there is immortality and impatience, it will be worth while to freeze yourself if the cost of cryo is less than the amount of money you make in this time, most likely through interest. This has nothing to do with the cost of living.
If there is immortality and patience, you could theoretically save money by going into cryostasis. In order for this to work, stasis would have to be cheaper than the net cost of living, including the money you make while living (not including interest). This will, in all probability, be below zero. People make enough to live on. As such, this would not be worth while.
I suppose it could mean that part of the labor force will freeze itself during economic slumps, since they won't be able to do much anyway. It would have to be cheaper than the cost of living by enough to make up for the possibility of getting a job even during a slump. I suppose if they set it up so you can get a job just as easily while frozen, then get waken up immediately, then people will start freezing themselves in this case.
I agree that people would probably hibernate as a solution to job loss, which would reduce labor market competition during economic slumps. During hibernation, they would not need housing, food, entertainment, or transportation. This would be easiest for single people -- though I suppose married couples or entire families and tight-knit social groups might arrange to hibernate simultaneously.
While labor market competition would become less desperate, the actual number of available candidates would go up, as employers would be able to thaw out prospective employees as soon as they acquire openings. The biggest danger would be to people who have obsolete skills or no skills, and also have no interest-bearing assets or passive income to pay their living expenses. They might end up stuck in indefinite stasis in a large government-run, energy-cost-optimized facility, as the less expensive alternative to welfare.
I dont think people would go into freeze just because that is cheaper than living. Being alive is still pretty awesome. I would not expect that much change. Humans are not that good at making long term financial plans.
I'm not proposing people will voluntarily opt to spend the rest of their existence in a suspended state just to save a few bucks, but there are a lot of circumstances where it would be convenient for people to stop existing, and then start existing again a little while later. If my partner and I wanted to buy a house, for example, it could be cheaper and faster for her to be on ice and me to live off dried pasta in a bedsit for six months than for us to simultaneously pay rent on a two-person place and save for a deposit.
I also find the assertion that little would change because of poor human long-term financial forecasting skills to be dubiously reasoned. The presence of cryo technology described above would provide more opportunities for people to make erroneous long-term financial plans. If I change my behaviour for a bad reason, I'm still changing it.
(It also has no impact on the removal of either human or investment capital; if that happened to a significant degree, it would fundamentally change a society's capacity for output. That might not result in a significant change in interest rates, but it's a bold claim to offhandedly say it won't.)
This is the obligatory post of the recent xkcd comic:
http://xkcd.com/989/