WASHINGTON — It was almost lunchtime at a food court downtown and Yonas A. Seyoum, the manager of the Esprinto Café, marched over to the cash register and printed out the morning’s sales.

“It’s crazy,” he said, holding up a drooping receipt.

He had done $52.71 of business in five hours, miserable even for January.

“Not even enough to pay her,” Mr. Seyoum said, motioning to the cashier, a young woman leaning on the counter and playing gin rummy on her phone.

He added: “It’s like a ghost city — totally dead.”

As the country nears the end of its third week of a government shutdown, the consequences of Washington’s political dysfunction are landing right on the city’s doorstep. The Washington metro area is home to the largest number of federal workers in the country, and as their paychecks begin to stop, the negative effects threaten to spread across the region.