With each passing generation, we find new and better ways of doing things. Yet during times of major economic disruption, change can come about much faster. In just a few short years, a number of fundamental shifts have occurred as cash-strapped consumers and companies break long-standing habits in an effort to save money.

For example, many consumers that had been loyal to certain food brands, such as Kellogg’s or Campbell’s, are more willing to try cheaper store brands to save on their grocery bill. When times improve, those consumers don’t always go back to the tried-and-true brands they used to purchase.

On the corporate level, companies have learned to use video conferencing during tough times to save on the high cost of business travel. When the economy rebounds, many employees have become so accustomed to video conferencing that it replaces the pricey business trips.

So even when the economy has improved, a return to the old ways seems highly unlikely. Here’s a short sample of four economic changes that now represent “the new normal.”

1. The number of banks keeps shrinking.

The economic slowdown has accelerated a trend that has been underway for two decades. Since 1990, thousands of local bank franchises have been swallowed up by national behemoths. That trend continues, augmented by a rising tide of shuttered banks. More than 300 banks have been closed by government regulators since the start of 2008, and if history is any guide, at least 100 more will be closed in 2011. This will result in fewer choices -- and less competition is usually a bad thing for consumers. Looking to profit from the trend? Many investors seek out solid local bank stocks – they can be good investments on their own and may appreciate nicely if caught up in the merger activity.

[Is your bank one of the next to fail? Find out in our Special Feature: The Next 442 Banks to Fail.]

2. U.S. carmakers are back in business.

The economic crisis led the bloated auto industry into turnaround mode. The major players were barely profitable in the good times, but have managed to become vastly profitable in much tougher times, thanks to a cost structure that has been forever changed -- via bankruptcy, in the case of GM (NYSE: GM), or via 'forced' cost reduction measures, as in the case of Ford (NYSE: F).

As an example, new hires at the major domestic auto makers must now settle for a lower hourly rate and fewer benefits than their more experienced colleagues have been accustomed to receiving. Some will scoff that a few years of good times will again lead to newfound bloat among Ford, GM and Chrysler, but the fundamental structural changes these companies have made are likely to become permanent. As a result, auto stocks have become better investments. I was a big fan of Ford in 2009, and now it looks as if GM may be the best sector investment for 2011.

3. The rise of the dollar stores.

The three major dollar stores -- (Family Dollar (NYSE: FDO), Dollar General (NYSE:DG) and Ninety-Nine Cents (NYSE: NDN) -- have seen their collective stock market value double since the end of 2007 as consumers trade down to discounters. Each of these chains looks poised for continued growth, even when the economy rebounds, and each is taking steps to create a more upscale appearance. They are stocking more traditional products, such as perishables and brand-name goods, boosting the price points well above $2 on occasion. Surveys indicate that an increasing number of shoppers that only started shopping at dollar stores in the last few years have expressed plans to stay with them even when times improve.

4. 20-somethings living at home.

The number of 20-somethings living with their parents has spiked 25% in just three years. Improving economic times might mitigate that trend somewhat, but it will be harder in the future to obtain a quick mortgage with low down payments and scant income verification. To meet a higher lending threshold, many 20-somethings will need to stay with their folks for an extended period until enough has been saved for a down payment.

Parents can help their kids move away from the nest by getting them to start saving at an early age. In some instances, parents are giving money as a wedding gift expressly intended as a down payment on a home.

[Get an early start teaching your children about saving and finances with this InvestingAnswers feature: How to Talk to Your Kids About the Financial Facts of Life.]

The economy has been dramatically altered in many ways over a relatively short period of time. As an investor, keeping track of these trends can help protect against any sudden shifts -- and could also lead to opportunities in the future.