“I’m thinking I need to stop eating out as much,” said Ana Smith, 24. She works for a consulting firm in Philadelphia and doesn’t get paid until this week. “It’ll affect my ability to shop.”

Paycheck Surprise

Smith was one of several diners in the food court at the Shops at Liberty Place, a retail complex in Philadelphia populated by many office workers who as of last week said they weren’t aware their paychecks were about to shrink. The increase in tax, to 6.2 percent of wages up to $113,700, will be used to pay for Social Security. It was reduced to a 4.2 percent rate in 2011 and 2012 to help ease the effects of the recession.

Most of the 134 million Americans who are on corporate payrolls will likely change their spending habits in similar ways to Williams and Smith, and that can add up to hundreds of millions of dollars across the economy, said Jerry Davis, a professor of sociology at the University of Michigan Ross School of Business in Ann Arbor, Michigan.

“Most Americans don’t bother to save much, so many people are living paycheck to paycheck and so small changes will quickly change behavior such as skipping meals or movies,” said Davis, who is also the Wilbur K. Pierpont Collegiate Professor of Management.

Paycheck to Paycheck

About 3.7 percent of an average American’s income is spent on recreation including things such as sporting events, movies and trips to the museum, according to November 2012 data from the U.S. Bureau of Economic Analysis. Another 5 percent goes toward food bought on the go, such as dining out, the data show.

A single person who makes $11,702, considered the poverty line in the U.S., will have $234 less in take-home pay a year. A family of two adults and two children at the poverty limit earns $22,811, subject to $456 more a year in taxes.

Even if the change seems small, Leslie Martinez said she worries the increased tax will affect her ability to pay bills on time or afford activities such as a movie night with her kids. The 32-year-old mother of two makes $17,000 a year working at a central Phoenix dry cleaner.

By the time she gets paid, there is already as little as $40 left, and the costs for her 12-year-old daughter to play soccer have been adding up recently. The changes will probably cut about $6.54 from her pay each week.