There’s a highly disturbing survey out from T. Rowe Price that looks into the investing habits of Generations X and Y circa now. It seems many Americans who still have decades of work ahead of them have decided that lowering their taxable income is not cool anymore and investing for the future is lame.

Too bad, because they’re obviously committing one of the cardinal sins of business: Saying no to the freebies. You’d think this would be obvious, and yet according to T. Rowe’s data, only 45% of people between 21 and 34 (Gen Y) and people between 35 and 50 (Gen X) will be making IRA contributions for fiscal 2011. That means a whopping percentage – more than half – will simply do nothing. This is down considerably from 2010, when 71% of those surveyed made contributions to their retirement plans.

This is unacceptable. When I speak with young investors (which many of my readers are), the first thing I tell them to do is contribute the maximum to their 401(k)s or 403(b)s – this before anything else. And if they are not at an employer with a plan, then establishing and contributing to an IRA is the next best option. What they do with the investing of that money is their choice but by not losing it to taxes, they’re ahead of the game.

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For the 2011 tax year, Gen X and Y (people under 50) can contribute $16,500 to their qualified retirement plans at work or put up to $5000 into an IRA. That money comes right off the top of their reportable income one way or the other — why anyone would say “screw it” to a deal like that I have no idea.

Are there any valid reasons for someone in their 20’s, 30’s or 40’s not to contribute? In my mind, there is only one: Financial hardship. If you are not making enough money to live or if you are unsure about whether you will in the near future, tax-deferred investing is not going to be the priority (for obvious reasons).

But no other excuses make any sense and as a result T. Rowe Price’s (TROW) study is a reminder of how foolish people can be when left to their own devices.

Not liking the economy or the stock market is not an excuse; people can contribute and leave it in cash if they absolutely must. It is important to keep in mind that from January to April 2009, one would have been making their fiscal 2008 contributions – a year in which not a soul alive “liked the economy” – but in hindsight, virtually any contribution allocated toward a stock mutual fund that spring turned out to be a grand slam purchase with the Dow Jones doubling just two years later.

Not feeling like dealing with the paperwork or the hassle of contributing is also not a valid excuse nor is the idea that one can be “all set for now” – each year we are taxed and each year we don’t “deal with it” we are paying taxes off of a higher base than we need to.

But it sounds as though 55% of Gen X and Y are going to deprive themselves of this advantage anyway. Unless they simply can’t afford it, they are essentially telling us that the dog ate their contribution.

Joshua Brown is a New York City-based investment advisor for high net worth individuals, charitable foundations, retirement plans and corporations. He blogs at TheReformedBroker.com.