The stock market is an amazing long-run wealth-creating machine. But to take part in it, you have to invest your hard-earned cash, putting it at risk today for the potential rewards it may bring you in the future. Finding the cash to invest in ordinary times is a tough enough prospect, but add the current economic conditions to the mix, and investing takes a special kind of dedication.

Wages, after all, have been increasing at a rate of less than 2% for the past several years, barely keeping up with the official inflation rate. Furthermore, Obamacare will lead to big premium increases in many states for typical individual health-insurance plans, according to the Manhattan Institute. While more inclusive coverage might reduce out-of-pocket expenses, the net impact on total health-care costs could still push up the amount the public has to pay overall faster than most people's salaries have grown to cover those costs.

Whenever costs rise faster than salaries, one of the easiest things to cut is savings. That will make it tougher for the ordinary people considered "retail investors" to invest for their futures.

You still have to invest
On the flip side, there are still several key reasons why most of us retail investors will keep plugging away, investing what we can, when we can.

For one, Social Security is on a collision course with an emptied Trust Fund and an expected 20%-25% reduction in benefits. For those of us who hope to live beyond the next 20 years, just about the only sane path is to invest to help make up that gap. Another Social Security-related reason to invest: A Trust Fund collapse is likely to be averted by cutting the rate at which payments increase, reducing an inflation adjustment that's already inadequate to cover seniors' costs.

A further item in favor of investment is that by holding down interest rates on government bonds through its quantitative-easing program, the Federal Reserve is purposely pushing investors farther out on the risk curve. In other words, if CDs and other "safe" investments pay a paltry 1% or so, investors who need a higher return just to make ends meet have to take on more risk. And with government bonds and other safe investments not providing real returns after inflation and taxes, that keeps money flowing to stocks.

For a third key reason, pensions are largely an artifact of the past, with companies largely replacing those defined benefit plans with defined contribution plans, like 401(k)s. That shift, plus an increased use of automatic enrollment (or "opt out") features, keeps people investing if they want any chance at a comfortable retirement.

Indeed, research from the Investment Company Institute suggests that people are continuing to invest in their 401(k)s and other defined contribution plans even as they slow their purchasing of mutual funds. That combination -- consistent 401(k) contribution and slower fund purchasing -- suggests ordinary retail investors are acting incredibly rationally.

So what will people do in 2014?
People's costs are rising, driven in large part by higher health-insurance premiums, but salaries haven't increased enough to compensate. As a result, people are prioritizing what they do with their money. What people can afford to invest is going into 401(k)s and other tax-advantaged retirement plans, while other investments are being sidelined as folks figure out how to cover their costs.

That trend, more than anything else, will likely continue through 2014. Whether higher costs force people to start drawing down their investments instead of simply slowing their rate of investing will depend on how well they can adapt the rest of their expenses. But with Social Security flagging, pensions no longer available for today's workforce, and the returns on safer savings held abysmally low, chances are that retail investors will do everything in their ability to keep investing.

Chuck Saletta is a Motley Fool contributor. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.