Despite years of public and private efforts to boost their social and economic status, blacks in L.A. County still lag other ethnic groups and blacks nationwide in key economic, health and education measures, according to a study released Wednesday.

The first-of-its kind report by the Los Angeles Urban League and United Way of Greater Los Angeles is aimed at painting an economic and quality-of-life portrait of blacks in the county and places blacks at the bottom in a comparative “equality index” of L.A.’s major ethnic groups, just under Latinos and well behind Asians and whites.

The report cites the lack of economic opportunity as the chief reason blacks trail other ethnic groups, with 54 percent of black households reporting income under $50,000 and one-fourth of blacks living below the poverty level.

“For many blacks in Los Angeles, this American dream is still out of reach,” the report states. “Stereotypes and misperceptions, unfair treatment by social institutions and the lack of access to resources that ensure equal participation make it a time of intense hardship, uncertainty and unfulfilled dreams.”

To help address the economic and social inequality, the report recommends some two-dozen steps in an ambitious “action agenda.” Among these: expanding living wage laws into high growth industries, boosting job-training programs for inmates, setting up an economic development council in South L.A. and allowing public housing residents to buy their units.

The report also recommends setting up programs to give parents a greater role in the classroom and better tracking of judges that routinely mete out “harsh” sentences to convicted defendants.

A similar-themed report issued by the United Way in the late 1990s called “A Tale of Two Cities” galvanized public attention around the issue of poverty and economic inequality in L.A. and prompted calls from public officials to boost various programs for the working poor. That report provided much of the impetus for “community benefits packages” that are now negotiated as part of redevelopment projects and for the current movement to set up mandatory affordable housing set-asides.