The overall undercount for the entire population was 2.1 percent.

The undercount for this category would thus be 1 percent.

The total undercount, he said, was closer to 3.5 million people.

"We know by that experience you'll always have an undercount," she said.

The government says it is too early to tell whether there was a black undercount without additional analysis, now under way.

Nationwide, the undercount was 4.7 million people, about 1.8 percent of the population.

Los Angeles officials are concerned about the financial impact of an undercount.

"We knew the undercount in the cities would be huge," he said.

This reluctance, of course, is not the only reason for an undercount.

In the District, which is two-thirds black, the undercount was nearly 7 percent.

"So we know there still will be an undercount, even with the bureau's best efforts."

Then, an undercount was estimated for each of the defined groups.

"We want to see the exact extent of the undercount in California."

The census was also noted for a significant undercount of the population.

The population undercount rate of the census was estimated at 0.12%.

A few public health researchers have noted the undercount in the past, based on their own academic studies.

Because the group relied mostly on media reports, the figure is likely an undercount.

Many of the other cities included in the report had similar or larger estimated undercounts.

"We have all the symptoms of an undercount," he said.

Opponents question whether there really has been a gross undercount.

The undercount was particularly heavy in black, Hispanic and other minority areas.

Still, no one knows how bad the undercount is.

"I think the large immigrant population is what drives up the undercount in my district."

The data also indicate that much of the undercount was concentrated in a few states.