Introduction to How the Census Works

In a country as large as the United States, how is it possible to count each person residing within its borders? Every 10 years, this is the impossible task that the Commerce Department's Census Bureau takes on. Census 2000 was billed by the bureau as "the largest peacetime effort in the history of the United States." You may recall some of the hoopla surrounding this effort in late 1999 and early 2000 as the nation prepared for National Census Day--April 1.

Counting seems to be the central theme of the United States in 2000, whether it be dimpled and pregnant chads or each citizen living from the tip of Maine to the Aleutian islands off the most western part of Alaska. If you live in the United States, there's a good chance that you received one of the 98 million census forms that were mailed out by the Census Bureau, and on April 1 an adult in each American household was supposed to fill out this form and send it in. More than eight months later, the official tally is in. Census 2000 shows that the resident population of the United States as of April 1, 2000, is 281,421,906. That is a 13.2 percent increase over 1990, when 248,709,873 were counted. See the Census Bureau for details.

The census is required by the U.S. Constitution under Article I Section 2, and is performed once a decade to do more than just satisfy our curiosity about the number of people that live in the country. In this edition of How Stuff Works, you'll learn how the census is actually taken, how its results are used to distribute federal funds and what impact the census has on the U.S. House of Representatives.

What Exactly Is the Census and How Long Has It Been Around?

The concept of a census, or counting of residents, is an ancient one dating to Biblical times. The first census ever taken in North America, historians say, was in 1576, 200 years before America gained its independence from the British. Spanish King Philip II, who then ruled the large region, sent American Indians through what is now Mexico with a list of 100 questions. The Indians spoke no Spanish, so they recorded the answers in hieroglyphs (pictures) and made maps the same way. (They even showed one-way streets with footprints!)

Since 1790, national census information has been taken every 10 years (in years ending in zero) because it is mandated by the U.S. Constitution and necessary to determining each area's representation in the U.S. House of Representatives. In 1790, George Washington signed the act into law. (Interestingly, several states had been taking their own census earlier and continued to do so in non-zero-ending years.) While the Constitution describes the census simply as an "enumeration of inhabitants," the census has evolved over time into a more comprehensive -- and more useful -- process. Now, we can learn much more about our population than just the number of people living in the United States.

According to Judy Hanna Green's book Finding Treasures in the U.S. Federal Census in 1790, the population of the United States was just under 4 million -- not counting slaves or the untaxed Indians. (A primary goal of the first census was to provide information on men eligible for the military. On the heels of the Revolutionary War, the new American citizens were especially conscious of the importance of a strong military. Later, during the War of 1812, much of the 1790 census was destroyed by fire.)

In the first national census, 17 U.S. marshals appointed 200 assistants. They rode on horseback all over the nation to count people, writing with quill pens (Read more about pen history at How a Ballpoint Pen Works!) on any scraps of paper they could find. The cost of that census project was $45,000!

Technology began to become part of census taking in 1890. The Census Bureau developed a new electrical machine that could add up responses to questions after census workers punched holes in the right places for each answer. Cards were then fed into a machine that totaled the result. It was bulky but a great advance at that time -- anything that sped up the process was a help since some of the results must be ready nine months after Census Day (more about that later).

The first modern computer, called ENIAC, was invented in 1946 at the University of Pennsylvania. This computer, which was really many machines working together, took up a whole room. The system was ready in time for use in parts of the 1950 census, and the Census Bureau ordered its own computer, called UNIVAC. That technology has improved over the years and now high-speed, supercomputers are available to assist the census.

Today, this technology plays a major role in the processing and census data. The major automation features for Census 2000 include data capture systems designed to handle the use of "respondent-friendly" questionnaires. The Census Bureau uses the National Processing Center and works with contractors who operate three processing centers responsible for a variety of data capture functions:

• A full electronic data capture and processing system records an image of every questionnaire.
• Questionnaires returned by mail will be sorted automatically to ensure timely capture of critical information needed before the non-response follow-up.
• Optical mark recognition will be used for all check-box data items.
• Intelligent character recognition (ICR) will be used to capture write-in character-based data items.
• A clerical keying operation will capture and resolve difficult ICR cases.
• A quality assurance review will be conducted on data keying and scanning activities.

Census Bureau officials say the use of electronic imaging and captured data in 2000 reduced the logistical and staffing requirements that accompany handling large volumes of paper questionnaires.

Most of the U.S. Census was taken door-to-door until 1960, when census officials recognized the inefficiency of this method in dealing with such a fast-growing, increasingly diverse and mobile population. That's when they decided to use the mail to distribute forms. In the 1970 census, about 60 percent was taken by mail, and in 1980, about 90 percent. However, in 1990, when the Census Bureau tried to take about 94 percent of the census by mail, one in three households failed to return the forms. That's why the most recent decennial census was the focus of a major, nationwide awareness campaign, officials say.

But neither technology nor mail have replaced the all-important census team members. Among the thousands of workers today are:

• Administrators -- They determine how each division of the Census Bureau will do its part in the census.
• Enumerators -- They go door-to-door to gather information from residents who have not returned their census forms.
• Statisticians -- They make sure the Census Bureau's math is right.
• Demographers -- These people understand the statistics and have studied what statistics tell about American life. They analyze the census numbers, comparing them with numbers from earlier censuses, and tell us important things about the future.

Why Is the Census Important?

Participating in the census is in everyone's best interest, because the information on the forms is used by decision-makers to determine which communities, schools, hospitals and roads need federal funding. Filling out your census form is also the best way to make sure people like you are represented in the census.

Here are just a few examples of important uses for census numbers:

• The federal government uses census numbers to allocate over $100 billion in federal funds annually for community programs and services, such as education programs, housing and community development, health-care services for the elderly, job training and many more.
• State, local and tribal governments use census information for planning and allocating funds for new school construction, libraries and other public buildings, highway safety and public transportation systems, new roads and bridges, location of police and fire departments and many other projects.
• Community organizations use census information to develop social service programs, community action projects, senior lunch programs and child-care centers.
• Businesses use the numbers to decide where to locate factories, shopping centers, movie theaters, banks and offices -- activities that often lead to new jobs.
• The U.S. Congress uses the census totals to determine how many seats your state will have in the U.S. House of Representatives. In addition, states use the numbers to allocate seats in their law-making bodies. President Clinton will deliver the apportionment counts to the 107th Congress during the first week of its regular session in January 2000. The reapportioned Congress, which will be the 108th, will convene in January 2003. This reapportionment of the 435 seats in the House of Representatives could have important political implications.

All that we learn about ourselves through the census will help the United States succeed over the next millennium. It's also a great way to tell our leaders who we are and what we need. If you need a closer-to-home reason for completing your census form, the Census Bureau suggests that you consider the following:

• You can help your community thrive. Does your neighborhood have a lot of traffic congestion, elderly people living alone or over-crowded schools? Census numbers can help your community work out public improvement strategies. Non-profit organizations use census numbers to estimate the number of potential volunteers in communities across the nation.
• You can make your government work for you. The hundreds of billions of dollars in federal and state funds allocated each year mean important things to you -- things such as school lunch programs, hospitals and highways! (Using census numbers to support their request for a new community center, senior citizens in one New England community successfully argued their case before county commissioners.)
• You can get help when you need it. Many 911 emergency systems are based on maps developed for the last census. Census information helps health providers predict the spread of diseases through communities with children or elderly people. And when floods, tornadoes or earthquakes hit, the census tells rescuers how many people will need their help.
• You can help American businesses. Census numbers help industry reduce financial risk and locate potential markets. This means that businesses are able to determine the marketability of potential products and come up products you want.
• You can get information you and your family need. Although individual records are held confidential for 72 years (more about that coming up!), you can request a certificate from past censuses that can be used to establish your age, residence or relationship -- information that could help you qualify for a pension, establish citizenship or obtain an inheritance. (In 2072, your great-grandchildren may want to use census information to research family history. Right now, your children may be using census information to do their homework.)

Census 2000 Is Big!

By law, the Census Bureau cannot share your answers with others, including welfare agencies, the Immigration and Naturalization Service, the Internal Revenue Service, courts, police and the military. Under the provisions of Title 13 of the U.S. Code, census bureau workers who break this law face up to five years in prison and $5,000 in fines. The law works -- millions of questionnaires were processed during the 1990s without any breach of trust.

This should also be reassuring: Did you know that the law requires each batch of census forms to remain private for 72 years? This is to encourage honesty and accurate information. The rationale behind this law is that little negative impact could happen after 72 years, since most of the people listed would be gone. So, this means that the latest census available to the public is the one taken in 1920.

The process of microfilming and printing the census also takes a long time to accomplish because of the 72-year wait and also by the sheer volume of documents. (This process usually takes another two years or so to complete and make ready for the public, according to bureau officials.)

First results of Census 2000 will be the state population totals used to reapportion the U.S. House of Representatives, which must be delivered to the President in exactly nine months -- by Dec. 31, 2000. More detailed data used to redraw U.S. and state legislative districts must be delivered to governors and state majority and minority leaders by April 1, 2001.

How Does the Census Process Actually Work?

In early March 2000, 98 million census forms -- both long and short forms -- went out in the mail to about 83 percent of the nation's residences. In addition, census enumerators personally delivered about 22 million additional forms to homes that lack street-name and house-number addresses, mostly in rural and remote areas. These represent about 17 percent of the nation's housing units. Hundreds of thousands of census takers and support personnel have been hired to account for the anticipated 118 million housing units and 275 million people across the United States.

The questionnaires were preceded by an advance letter sent a week or so earlier. This letter gave residents the option of asking for questionnaires in five languages besides English: Spanish, Tagalog, Korean, Chinese and Vietnamese. Later this month (March), the Census Bureau then sent a reminder card asking residents to mail back the form as soon as possible.

During March of a census year, the Census Bureau conducts special operations to count people with no fixed address or who live in dormitories, nursing homes, prisons, shelters, trailer parks, transient housing and other groups or non-standard housing.

After April 1, census workers spend a couple of months trying to locate and get information from households or families that failed to respond by mail. If your questionnaire is incomplete, a census employee must contact you to obtain the missing information. Then these answers are combined with those on your questionnaire. It is these combined numbers --not your individual answers -- that are published.

As census methodology has become more sophisticated, researchers have begun to learn more about who responds and who doesn't. For example, the overall non-response rate in 1990 was 25.3 percent. Researchers say response -- or lack of response -- to the mailed 1990 Census questionnaires was highly correlated with race and length of time at a residence. Researchers also said that mail response to the 1990 Census was strongly related to family composition (the number of parents in the home, the age of the single parent, etc.).

How Can Homeless and Transient People Be Counted?

According to the Census Bureau, it enlists the help of local experts in finding places where people without housing receive services, such as emergency and transitional shelters, soup kitchens, regularly-scheduled mobile food vans and targeted outdoor locations. Census workers go to these locations to conduct the census.

Partnerships with community-based organizations are essential to including migrant and seasonal farm workers in the census. The Census Bureau seeks the advice of local experts to find areas where migrant and seasonal workers live and work, including unregistered labor camps, vehicles parked near work sites and living areas along unnamed roads.

Census takers interview people staying at campgrounds, fairs and carnivals and marinas. Every person interviewed has the opportunity to report his or her permanent address.

Other Special Groups

There are a number of other special groups that require special planning. There are special procedures for ensuring that census information for people living in remote areas is accurate. For example, in remote Alaska, the census must be completed before the spring thaw. After the thaw, many residents are away from their homes hunting or conducting other spring activities. By then it is too late for counters to contact them.

And the Census Bureau works with the Department of Defense and the U.S. Coast Guard to identify living quarters on military installations and ships. All ocean-going, coastal and Great Lake ships take part in what is known as the Census Maritime Enumeration. In addition, the Census Bureau's plan accounts for military personnel and federal civilian government employees, as well as their dependents, who are stationed overseas.

When necessary, census takers assist residents who need help in completing the forms. In some facilities, such as jails, the staff distributes census questionnaires. These staff workers, like all census workers, are sworn to protect the confidentiality of the individual.

A complete set of residence rules telling where students, nursing home residents, military personnel and others are counted can be found on the Census Bureau's Web site.

What About Children? Are They Counted?

While considerable attention has been devoted to the undercount for the U.S. population overall and to specific sub-groups such as young black men in inner cities, less attention has been given to the undercount of children.

In an attempt to help remedy that problem, the Census Bureau has provided more than 300,000 Census in Schools kits throughout the country. The purpose of the kits is to increase participation in the census among children and parents. "In 1990, many parents did not record children on their census questionnaire," Bureau Director Kenneth Prewitt said. "This program is one way we hope to ensure that every child is counted. We hope parents will urge their schools and that teachers will urge their principals to take part in the Census in Schools program."

The program provides students with a take-home letter explaining to parents the importance of an accurate census. The letter is available in English, Spanish, Chinese, Vietnamese, Tagalog and Korean. Additional take-home materials provide recreational census activities for students to complete with their parents. Sent to the schools in February, each program teaching guide contains lesson plans that address map literacy, community involvement and information management. Kits are available for grades K-4, 5-8 and 9-12. Custom designed teaching kits were sent to schools in Puerto Rico, the U.S. Virgin Islands, Guam, American Samoa and the Commonwealth of the Northern Mariana Islands. (Scholastic Inc. helped to develop the program's teaching materials, most of which can be downloaded from the bureau's Web site.)

What Is the Form Like?

In 2000, the Census Bureau sent out about 83 million short forms (with seven questions) and 15 million long forms (with 52 questions). Prewitt says the short form asks for less information than is found on your driver's license and takes about 10 minutes to complete. The long form takes about 38 minutes, he estimates. Although the rate varies according to population density, in most areas about 5 out of 6 homes will receive the short form, while the remaining 1 out of 6 will receive the long form. (In some rural areas, as many as every other home may receive this long form, because a larger sample is needed to ensure that these towns and counties get the same detailed information as more densely populated areas.)

The questionnaires have room for information on six household members. If you have more than six living in your home, you should fill in the additional names, and a Census Bureau representative will contact you for more information.

The short form -- the shortest in 180 years -- contains six population questions and one housing question. The long form has 31 population questions (including the six short-form population questions) and 21 housing questions (including the short-form housing question). Questions are included on the census questionnaire only if they serve a legal or programmatic need, according to census officials. (For information on these reasons, see the Census Bureau's Web site.)

For the first time, the 2000 census allowed you to identify yourself as being more than one race. Participants in the census had the choice of checking off as many race categories as they wished. Hispanics may be of any race; therefore, there is one question on Hispanic origin and another on race.

The only additional documents you need to help you complete the form are income tax forms and property tax and homeowners' payment records. (Only a few figures are needed.)

What If I Have Questions About My Form?

The Census Bureau will help you. Start by looking at these Help and Information sites. In addition to the Census Bureau's very comprehensive Web site, there are also questionnaire assistance centers in your community, and a toll-free telephone number to call for assistance is written on the form you received in the mail. If you've lost your form or didn't receive one, you can call your local or regional center to find out where to get one.

When you think about it, participating in Census 2000 is being a part of history in the making. As the Census 2000 slogan goes: "It's your future -- don't leave it blank."

Links

• U.S. Census Bureau Home Page
• 1990 U.S. Census
• More on the Census Form
• Census 2000 Jobs
• Residence Rules
• Finding Treasures in the U.S. Federal Census by Judy Hanna Green
• Last Pre-Census Estimate of 1990-99 Population
• International Statistics Agencies
• State and County Demographic and Economic Profiles