College graduates earned less coming out of the recession, according to a May study by the John J. Heldrich Center for Workforce Development at Rutgers. Those graduating during 2009 to 2011 earned a median salary in their starting job $3,000 less than the $30,000 seen in 2007. The majority of students owed $20,000 to pay off their education, and 40 percent of the 444 college graduates surveyed said their loan debt is causing them to delay major purchases such as a house or a car. The U.S. Consumer Financial Protection Bureau said in March it appeared student loans had reached $1 trillion "several months" earlier.

U.S. Economy

The U.S. economy shrank 4.7 percent from December 2007 to June 2009, making it the deepest and longest slump in the post- war era. In the three years since the recession ended, the economy has expanded 6.7 percent, the weakest recovery since World War II.

Even as the housing market shows some signs of revival, the slow pace of recovery is keeping the younger generation fearful of investments rather than confident about building wealth for the future, said Jeffrey Lubell, executive director for the Center for Housing Policy, based in Washington. First-time home buyers in 2011 accounted for the smallest percentage of the total since 2006, according to the National Association of Realtors. The vacancy rate of U.S. rental properties is at its lowest level since 2002.

The shifting attitudes also pose a threat to retail sales, said Candace Corlett, president of New York-based retail- strategy firm WSL Strategic Retail. Younger consumers are already comfortable buying used items and borrowing from friends. Renting will only reinforce their tendency not to buy new.

Post-Recession

"In a post-recession economy where retailers are trying to make every shopper count, it's the wrong direction," she said. Retail sales fell in June for a third consecutive month, the longest period of declines since 2008.

The by-the-hour segment accounts for about 6 percent of the $30.5 billion U.S. car-rental market, a share that is forecast to rise to about 10 percent in five years, according to IBISWorld.

St. Louis-based Enterprise, the largest U.S. car-rental company, expanded in the segment in May by acquiring Mint Cars On-Demand, an hourly car-rental firm with locations in New York and Boston. Half of Enterprise's customers in this segment are under 35, according to company spokeswoman Laura Bryant.

Hertz, which began renting cars by the hour in 2008, plans to equip its entire 375,000-vehicle U.S. fleet with the technology for hourly rental within about a year, said Richard Broome, senior vice president of corporate affairs and communications for the Park Ridge, New Jersey-based company.

Fuel Costs

"It made sense to reach the younger demographic to get involved in car sharing," Broome said. Those 34 and younger make up 84 percent of Hertz's by-the-hour customer base, he said. "The higher costs of insurance, the higher costs of fuel, the economics would lead someone to conclude that it's a better decision to rent the car or do car sharing than it is to own a car."