If you invite eight people to dinner and a dozen arrive, you could be in trouble. The trouble multiplies dramatically when you set the table for 221.7 million people -- the US Census Bureau's current United States population estimate for 1980 -- and an extra 5 million show up.
Given the Census Bureau's history of undercounting the US population and the vital role the decennial head count plays in deciding the number of places set at the federal table, two cities have turned to the courts to help ensure an accurate count of their residents.
Detroit is suing the Census Bureau to require an "adjusted" figure to reflect the city's entire population. Chicago's Hispanic-Americans are suing to force the Census Bureau to hire more Spanish-speaking workers immediately to send into entire blocks in West Chicago that are said to have never received census forms.
According to Joseph Baltimore, an attorney for the City of Detroit, greater accuracy and fairness could be achieved by switching from door-to-door head counts to a statistical estimate of the population.
The suits, which lawyers involved feel could be followed by more in New York, Texas, and California, spring directly from the Census Bureau's own evaluation of its 1970 figures.
According to the bureau's estimates after three years of post-census research , it undercounted the US population in 1970 by some 5.3 million people, or 2.5 percent. The bureau estimates that its overall 2.5 percent undercount 10 years ago was 1.9 percent among the nation's 180 million whites but 7.7 percent among the 23 million blacks. Others estimate that Hispanics, who were not listed separately in 1970, may have suffered a 15 percent undercount.
Census Bureau spokesman Henry Smith explains that the 7.7 percent undercount among blacks meant that "blacks proportionately lost more" federal funds.
The two cities' legal action follows another suit, filed by the Federation for American Immigration Reform (FAIR), charging the bureau with overcountingm by including illegal aliens. FAIR's suit is awaiting US Supreme Court action.
Michael Ferrell, staff director for the House subcommittee on census and population, warns, that Census Bureau inflexibility could result in "litigating the 1980 census through the next four or five years."
The stakes involved in these actions are high. The final population figures that the bureau delivers to President Carter Dec. 31 will decide how up to $75 billion in funds for housing, education, employment, medical, and other federal programs is to be divided among different part of the country, between urban and rural areas, and between ethnic groups.
Moreover, population shifts recorded in the 1980 cesus probably will give the South and West 14 new seats in the US House of Representatives at the expense of the Northeast and Midwest.
With so much money and so many congressional seats on the line, the Census Bureau has been under increasing pressure. Critics charge it with failing to carry out its constitutional duty to make an accurate count of the population every 10 years.
The US General Accountting Office concluded in a 1976 study that it is "doubtful" whether the bureau can reduce its traditional undercount of the population.
The Census Bureau responded to earlier criticisms by starting work on the 1980 census in 1974.
To achieve a more accurate count, the cost of the census is up to $1 billion for 1980 -- more than $4 a person counted -- compared with $221 million for 1970 .
Minority groups and the major cities that host large minority populations have been determined not to be shortchanged when federal funds are divided.
Minority leaders emphasized the confidentiality of the census, distributed information in Spanish and other languages, and emphasized that every uncounted person costs his community some $230 in federal funds.
Mr. Smith stresses that this year's count will continue for another two months as evaluators knock on more doors to find the uncounted.