"The muted response may be due to consumers giving progressively less credence to the economic scare tactics that have framed the debates over the past few years," he said.
Still, stocks rose for a third day as talks between President Obama and lawmakers continued with the understanding that neither party would be willing to let the nation breach the $16.7 trillion debt ceiling when the deadline hits next week.
Business groups, from manufacturers to retailers, have implored Congress and the White House to forge a deal that would reopen the federal government and raise the debt ceiling.
Hundreds of thousands of federal employees are still furloughed while policymakers attempt to hammer out an agreement.
Economists argued on Friday that the prolonged shutdown is depressing economic growth and will intensify the longer it lasts.
Mark Zandi, chief economist of Moody's Analytics, said he is expecting a 0.5 percentage point decrease in the fourth quarter growth figure — down to 2 percent from 2.5.
Consumer sentiment about current conditions actually rose slightly to 92.8 in October from 92.6.
But the six-month forecast posted its weakest result of the year, dropping to 63.9 from 67.8 in September.
"To be sure, this can quickly change if the impasse continues," Curtin said.
Congress will take the shutdown into this weekend with the aim to work out a deal before the Treasury runs out of "extraordinary measures" to pay the nation's bills on Thursday.
The federal government is scheduled to be off on Monday for Columbus Day, but the House is scheduled to be in session and the Senate will likely follow suit.