A report released Thursday that provided new details on the region's homeless population prompted Mayor Antonio Villaraigosa to call the nation's second-largest city the nation's "capital of homelessness."

The report by the Los Angeles Homeless Services Authority estimated that 82,291 people were homeless in Los Angeles County on any given night in 2005, with about 48,103 of the county's homeless living within Los Angeles' city limits.

The estimates mark the first attempt to gather detailed data on the homeless. The figures will provide a benchmark to evaluate the effectiveness of programs to curb homelessness, officials said.

The study also reported that California's estimated homeless population of 195,367 is the highest in the nation. Forty-six percent of the state's homeless population is located in Los Angeles County, according to researchers, who determined that one of every 110 people in the county are homeless on any given night.

"This is the capital of homelessness in the United States of America. It dwarfs the homeless problem anywhere in the state, and the city of Los Angeles is ground zero for it," Villaraigosa said.

The survey estimated that about 49 percent of the county's homeless population could be considered chronically homeless.

A chronic homeless person was defined as someone with a "disabling condition," such as mental illness or drug use, who has been homeless for a year or more or who has been homeless four or more times within the past three years.

The Los Angeles Homeless Services Authority conducted a three-day homeless count in January 2005 and preliminary results were released last June. The new report included data from field surveys, telephone surveys and statistical analyses.

Villaraigosa said the city's attempts to address the homelessness issue will include the aggressive pursuit of funds from Proposition 63, the measure to expand mental health programs by taxing millionaires 1 percent.

Voters approved the measure in November 2004.