A ZIP Code is a postal code used by the United States Postal Service in a system it introduced in 1963. The term ZIP is an acronym for Zone Improvement Plan; the basic format consists of five digits. An extended ZIP+4 code was introduced in 1983 which includes the five digits of the ZIP Code, followed by a hyphen and four additional digits that reference a more specific location; the term ZIP Code was registered as a servicemark by the U. S. Postal Service, but its registration has since expired; the early history and context of postal codes began with postal district/zone numbers. The United States Post Office Department implemented postal zones for numerous large cities in 1943. For example: The "16" was the number of the postal zone in the specific city. By the early 1960s, a more organized system was needed, non-mandatory five-digit ZIP Codes were introduced nationwide on July 1, 1963; the USPOD issued its Publication 59: Abbreviations for Use with ZIP Code on October 1, 1963, with the list of two-letter state abbreviations which are written with both letters capitalized.
An earlier list in June had proposed capitalized abbreviations ranging from two to five letters. According to Publication 59, the two-letter standard was "based on a maximum 23-position line, because this has been found to be the most universally acceptable line capacity basis for major addressing systems", which would be exceeded by a long city name combined with a multi-letter state abbreviation, such as "Sacramento, Calif." along with the ZIP Code. The abbreviations have remained unchanged, with the exception of Nebraska, changed from NB to NE in 1969 at the request of the Canadian postal administration, to avoid confusion with the Canadian province of New Brunswick. Robert Moon is considered the father of the ZIP Code; the post office only credits Moon with the first three digits of the ZIP Code, which describe the sectional center facility or "sec center." An SCF is a central mail processing facility with those three digits. The fourth and fifth digits, which give a more precise locale within the SCF, were proposed by Henry Bentley Hahn Sr.
The SCF sorts mail to all post offices with those first three digits in their ZIP Codes. The mail is sorted according to the final two digits of the ZIP Code and sent to the corresponding post offices in the early morning. Sectional centers do not deliver mail and are not open to the public, most of their employees work the night shift. Mail picked up at post offices is sent to their own SCF in the afternoon, where the mail is sorted overnight. In the case of large cities, the last two digits coincide with the older postal zone number thus: In 1967, these became mandatory for second- and third-class bulk mailers, the system was soon adopted generally; the United States Post Office used a cartoon character, which it called Mr. ZIP, to promote the use of the ZIP Code, he was depicted with a legend such as "USE ZIP CODE" in the selvage of panes of postage stamps or on the covers of booklet panes of stamps. In 1971 Elmira Star-Gazette reporter Dick Baumbach found out the White House was not using a ZIP Code on its envelopes.
Herb Klein, special assistant to President Nixon, responded by saying the next printing of envelopes would include the ZIP Code. In 1983, the U. S. Postal Service introduced an expanded ZIP Code system that it called ZIP+4 called "plus-four codes", "add-on codes", or "add-ons". A ZIP+4 Code uses the basic five-digit code plus four additional digits to identify a geographic segment within the five-digit delivery area, such as a city block, a group of apartments, an individual high-volume receiver of mail, a post office box, or any other unit that could use an extra identifier to aid in efficient mail sorting and delivery. However, initial attempts to promote universal use of the new format met with public resistance and today the plus-four code is not required. In general, mail is read by a multiline optical character reader that instantly determines the correct ZIP+4 Code from the address—along with the more specific delivery point—and sprays an Intelligent Mail barcode on the face of the mail piece that corresponds to 11 digits—nine for the ZIP+4 Code and two for the delivery point.
For Post Office Boxes, the general rule is. The add-on code is one of the following: the last four digits of the box number, zero plus the last three digits of the box number, or, if the box number consists of fewer than four digits, enough zeros are attached to the front of the box number to produce a four-digit number. However, there is no uniform rule, so the ZIP+4 Code must be looked up individually for each box; the ZIP Code is translated into an Intelligent Mail barcode, printed on the mailpiece to make it easier for automated machines to sort. A barcode can be printed by the sender, it is better to let the post office put one on. In general, the post office uses OCR technology, though in some cases a human might have to read and enter the address. Customers who send bulk mail can get a discount on postage if they have printed the barcode themselves and have presorted the mai
Hispanic and Latino Americans
Hispanic Americans and Latino Americans are Americans who are descendants of people from Spain and Latin America, respectively. More it includes all Americans who speak the Spanish language natively, who self-identify as Hispanic or Latino, whether of full or partial ancestry. For the 2010 United States Census, people counted as "Hispanic" or "Latino" were those who identified as one of the specific Hispanic or Latino categories listed on the census questionnaire as well as those who indicated that they were "other Spanish, Hispanic or Latino." The national origins classified as Hispanic or Latino by the United States Census Bureau are the following: Argentine, Colombian, Puerto Rican, Mexican, Costa Rican, Honduran, Panamanian, Bolivian, Spanish American, Ecuadorian, Peruvian and Venezuelan. Brazilian Americans, other Portuguese-speaking Latino groups, non-Spanish speaking Latino groups in the United States are defined as "Latino" by some U. S. government agencies. The Census Bureau uses the terms Hispanic and Latino interchangeably."Origin" can be viewed as the ancestry, nationality group, lineage or country of birth of the person or the person's parents or ancestors before their arrival in the United States.
People who identify as Spanish, Hispanic or Latino may be of any race. As one of the only two designated categories of ethnicity in the United States, Hispanics form a pan-ethnicity incorporating a diversity of inter-related cultural and linguistic heritages. Most Hispanic Americans are of Mexican, Puerto Rican, Salvadoran, Guatemalan or Colombian origin; the predominant origin of regional Hispanic populations varies in different locations across the country. Hispanic Americans are the second fastest-growing ethnic group by percentage growth in the United States after Asian Americans. Hispanic/Latinos overall are the second-largest ethnic group in the United States, after non-Hispanic whites. Hispanics have lived within what is now the United States continuously since the founding of St. Augustine by the Spanish in 1565. After Native Americans, Hispanics are the oldest ethnic group to inhabit much of what is today the United States. Many have Native American ancestry. Spain colonized large areas of what is today the American Southwest and West Coast, as well as Florida.
Its holdings included present-day California, New Mexico, Nevada and Texas, all of which were part of the Republic of Mexico from its independence in 1821 until the end of the Mexican–American War in 1848. Conversely, Hispanic immigrants to the New York-New Jersey metropolitan area derive from a broad spectrum of Latin American states. A study published in 2015 in the American Journal of Human Genetics, based on 23andMe data from 8,663 self-described Latinos, estimated that Latinos in the United States carried a mean of 65.1% European ancestry, 18.0% Native American ancestry, 6.2% African ancestry. The study found that self-described Latinos from the Southwest those along the Mexican border, had the highest mean levels of Native American ancestry; the terms "Hispanic" and "Latino" refer to an ethnicity. Hispanic people may share some commonalities in their language, culture and heritage. According to the Smithsonian Institution, the term "Latino" includes peoples with Portuguese roots, such as Brazilians, as well as those of Spanish-language origin.
In the United States, many Hispanics and Latinos are of both Native American ancestry. Others are predominantly of European ancestry or of Amerindian ancestry. Many Hispanics and Latinos from the Caribbean, as well as other regions of Latin America where African slavery was widespread, may be of sub-Saharan African descent as well; the difference between the terms Hispanic and Latino is confusing to some. The U. S. Census Bureau equates the two terms and defines them as referring to anyone from Spain and the Spanish-speaking countries of the Americas. After the Mexican–American War concluded in 1848, term Hispanic or Spanish American was used to describe the Hispanos of New Mexico within the American Southwest; the 1970 United States Census controversially broadened the definition to "a person of Mexican, Puerto Rican, South or Central American, or other Spanish culture or origin, regardless of race". This is now the common formal and colloquial definition of the term within the United States, outside of New Mexico.
The term Latino has developed a number of definitions. One definition of Latino is "a Latin male in the United States"; this is the oldest and the original definition used in the United States, first used in 1946. This definition encompasses Spanish speakers from both Europe and the Americas. Under this definition, immigrants from Spain and immigrants from Latin America are both Latino; this definition is consistent with the 21st-century usage by the U. S. Census Bureau and OMB, as the two agencies use Latino interchangeably. A definition of Latino is as a condensed form of the term "Latino-Americano", the Spanish word for Latin-American, or someone who comes from Latin America. Under this definition a Mexican American or Puerto Rican, for example, is both a Hispanic and a Latino. A Brazilian American is a Latino by this definition, which includes those of Portuguese-speaking origin from Latin America. However, an immigrant from Spain would be classified as European or White by American sta
Marriage called matrimony or wedlock, is a or ritually recognised union between spouses that establishes rights and obligations between those spouses, as well as between them and any resulting biological or adopted children and affinity. The definition of marriage varies around the world not only between cultures and between religions, but throughout the history of any given culture and religion, evolving to both expand and constrict in who and what is encompassed, but it is principally an institution in which interpersonal relationships sexual, are acknowledged or sanctioned. In some cultures, marriage is recommended or considered to be compulsory before pursuing any sexual activity; when defined broadly, marriage is considered a cultural universal. A marriage ceremony is known as a wedding. Individuals may marry for several reasons, including legal, libidinal, financial and religious purposes. Whom they marry may be influenced by gender determined rules of incest, prescriptive marriage rules, parental choice and individual desire.
In some areas of the world, arranged marriage, child marriage and sometimes forced marriage, may be practiced as a cultural tradition. Conversely, such practices may be outlawed and penalized in parts of the world out of concerns of the infringement of women's rights, or the infringement of children's rights, because of international law. Around the world in developed democracies, there has been a general trend towards ensuring equal rights within marriage for women and recognizing the marriages of interfaith and same-sex couples; these trends coincide with the broader human rights movement. Marriage can be recognized by a state, an organization, a religious authority, a tribal group, a local community, or peers, it is viewed as a contract. When a marriage is performed and carried out by a government institution in accordance with the marriage laws of the jurisdiction, without religious content, it is a civil marriage. Civil marriage recognizes and creates the rights and obligations intrinsic to matrimony before the state.
When a marriage is performed with religious content under the auspices of a religious institution it is a religious marriage. Religious marriage recognizes and creates the rights and obligations intrinsic to matrimony before that religion. Religious marriage is known variously as sacramental marriage in Catholicism, nikah in Islam, nissuin in Judaism, various other names in other faith traditions, each with their own constraints as to what constitutes, who can enter into, a valid religious marriage; some countries do not recognize locally performed religious marriage on its own, require a separate civil marriage for official purposes. Conversely, civil marriage does not exist in some countries governed by a religious legal system, such as Saudi Arabia, where marriages contracted abroad might not be recognized if they were contracted contrary to Saudi interpretations of Islamic religious law. In countries governed by a mixed secular-religious legal system, such as in Lebanon and Israel, locally performed civil marriage does not exist within the country, preventing interfaith and various other marriages contradicting religious laws from being entered into in the country, civil marriages performed abroad are recognized by the state if they conflict with religious laws.
The act of marriage creates normative or legal obligations between the individuals involved, any offspring they may produce or adopt. In terms of legal recognition, most sovereign states and other jurisdictions limit marriage to opposite-sex couples and a diminishing number of these permit polygyny, child marriages, forced marriages. In modern times, a growing number of countries developed democracies, have lifted bans on and have established legal recognition for the marriages of interfaith and same-sex couples; some cultures allow the dissolution of marriage through annulment. In some areas, child marriages and polygamy may occur in spite of national laws against the practice. Since the late twentieth century, major social changes in Western countries have led to changes in the demographics of marriage, with the age of first marriage increasing, fewer people marrying, more couples choosing to cohabit rather than marry. For example, the number of marriages in Europe decreased by 30% from 1975 to 2005.
In most cultures, married women had few rights of their own, being considered, along with the family's children, the property of the husband. In Europe, the United States, other places in the developed world, beginning in the late 19th century and lasting through the 21st century, marriage has undergone gradual legal changes, aimed at improving the rights of the wife; these changes included giving wives legal identities of their own, abolishing the right of husbands to physically discipline their wives, giving wives property rights, liberalizing divorce laws, providing wives with reproductive rights of their own, requiring a wife's consent when sexual relations occur. These changes have occurred in Western countries. In the 21st century, there continue to be controversies regarding the legal status of married women, legal acceptance of or leniency towards violence within marriage, traditional marriage customs such as dowry and bride price, for
South Los Angeles
South Los Angeles is a region in southern Los Angeles County and lies within the city limits of Los Angeles, just south of downtown. According to the Los Angeles Times, South Los Angeles ”is defined on Los Angeles city maps as a 16-square-mile rectangle with two prongs at the south end.” In 2003, the Los Angeles City Council renamed this area "South Los Angeles". The name South Los Angeles can refer to a larger 51-square mile area that includes areas within the city limits of Los Angeles as well as five unicorporated neighborhoods in the southern portion of the County of Los Angeles; the City of Los Angeles delineates South Los Angeles as an area of 15.5 square miles. Adjacent neighborhoods include West Adams, Baldwin Hills, Leimert Park to the west and the Southeast Los Angeles region of the city on the east. According to the Los Angeles Times Mapping Project, South Los Angeles comprises 51 square miles, consisting of 25 neighborhoods within the City of Los Angeles as well as three unincorporated neighborhoods in the County of Los Angeles.
Google Maps delineates a similar area to the Los Angeles Times Mapping Project with notable differences on the western border. On the northwest, it omits a section of Los Angeles west of La Brea Avenue. On the southwest, it includes a section of the City of Inglewood north of Century Boulevard. According to the Mapping L. A. survey of the Los Angeles Times, the South Los Angeles region consists of the following neighborhoods: In 1880, the University of Southern California, in 1920, the Doheny Campus of Mount St. Mary's College, were founded in South Los Angeles; the 1932 and 1984 Olympic Games took place near the USC campus at neighboring Exposition Park, where the Los Angeles Coliseum is located. Until the 1920s, the South Los Angeles neighborhood of West Adams was one of the most desirable areas of the City; as the wealthy were building stately mansions in West Adams and Jefferson Park, the white working class was establishing itself in Crenshaw and Hyde Park. Affluent blacks moved into West Adams and Jefferson Park.
As construction along the Wilshire Boulevard corridor increased in the 1920s, the development of the city was drawn west of downtown and away from South Los Angeles. At the same time, the area of modest bungalows and low-rise commercial buildings along Central Avenue emerged as the heart of the black community in southern California, it had one of the first jazz scenes in the western U. S. with trombonist Kid Ory a prominent resident. Under racially restrictive covenants, blacks were allowed to own property only within the Main-Slauson-Alameda-Washington box and in Watts, as well as in small enclaves elsewhere in the city; the working- and middle-class blacks who poured into Los Angeles during the Great Depression and in search of jobs during World War II found themselves penned into what was becoming a overcrowded neighborhood. During the war, blacks faced such dire housing shortages that the Housing Authority of the City of Los Angeles built the all-black and Latino Pueblo Del Rio project, designed by Richard Neutra.
When the Supreme Court banned the legal enforcement of race-oriented restrictive covenants in 1948's Shelley v. Kraemer, blacks began to move into areas outside the overcrowded Slauson-Alameda-Washington-Main settlement area. For a time in the early 1950s, southern Los Angeles became the site of significant racial violence, with whites bombing, firing into, burning crosses on the lawns of homes purchased by black families south of Slauson. In an escalation of behavior that began in the 1920s, white gangs in nearby cities such as South Gate and Huntington Park accosted blacks who traveled through white areas; the black mutual protection clubs that formed in response to these assaults became the basis of the region's fearsome street gangs. As in most urban areas, 1950s freeway construction radically altered the geography of southern Los Angeles. Freeway routes tended to reinforce traditional segregation lines. Beginning in the 1970s, the rapid decline of the area's manufacturing base resulted in a loss of the jobs that had allowed skilled union workers to have a middle class life.
Downtown Los Angeles' service sector, which had long been dominated by unionized African Americans earning high wages, replaced most black workers with newly arrived Mexican and Central American immigrants. Widespread unemployment and street crime contributed to the rise of street gangs in South Central, such as the Crips and Bloods, they became more powerful with money from drugs the crack cocaine trade, dominated by gangs in the 1980s. By the early 2000s, the crime rate of South Los Angeles had declined significantly. Redevelopment, improved police patrol, community-based peace programs, gang intervention work, youth development organizations lowered the murder and crime rates to levels that had not been seen since the 1940s and'50s. South Los Angeles was still known for its gangs at the time. In mid 2003, the City of Los Angeles changed the region's name from South Central to South Los Angeles, a move supporters said would "help erase a stigma that has dogged the southern part of the city."On August 11, 2014, just two days after the shooting of Michael Brown in Ferguson, Missouri, a resident of South L.
A. Ezell Ford, described as "a mentally ill 25-year-old man," was fatally shot by two Los Angeles police officers. Since a number of protests focused on events in Ferguson have taken place in South Los Angeles. After the 2008 economic recession, housing prices in South Los Angeles recovered and by 2018, many had come to see South Los Angeles as a
North American Numbering Plan
The North American Numbering Plan is a telephone numbering plan that encompasses twenty-five distinct regions in twenty countries in North America, including the Caribbean. Some North American countries, most notably Mexico, do not participate in the NANP; the NANP was devised in the 1940s by AT&T for the Bell System and independent telephone operators in North America to unify the diverse local numbering plans, established in the preceding decades. AT&T continued to administer the numbering plan until the breakup of the Bell System, when administration was delegated to the North American Numbering Plan Administration, a service, procured from the private sector by the Federal Communications Commission in the United States; each participating country forms a regulatory authority that has plenary control over local numbering resources. The FCC serves as the U. S. regulator. Canadian numbering decisions are made by the Canadian Numbering Administration Consortium; the NANP divides the territories of its members into numbering plan areas which are encoded numerically with a three-digit telephone number prefix called the area code.
Each telephone is assigned a seven-digit telephone number unique only within its respective plan area. The telephone number consists of a four-digit station number; the combination of an area code and the telephone number serves as a destination routing address in the public switched telephone network. For international call routing, the NANP has been assigned the international calling code 1 by the International Telecommunications Union; the North American Numbering Plan conforms with ITU Recommendation E.164, which establishes an international numbering framework. From its beginnings in 1876 and throughout the first part of the 20th century, the Bell System grew from local or regional telephone systems; these systems expanded by growing their subscriber bases, as well as increasing their service areas by implementing additional local exchanges that were interconnected with tie trunks. It was the responsibility of each local administration to design telephone numbering plans that accommodated the local requirements and growth.
As a result, the Bell System as a whole developed into an unorganized system of many differing local numbering systems. The diversity impeded the efficient operation and interconnection of exchanges into a nationwide system for long-distance telephone communication. By the 1940s, the Bell System set out to unify the various numbering plans in existence and developed the North American Numbering Plan as a unified, systematic approach to efficient long-distance service that did not require the involvement of switchboard operators; the new numbering plan was accepted in October 1947, dividing most of North America into eighty-six numbering plan areas. Each NPA was assigned a numbering plan area code abbreviated as area code; these codes were first used by long-distance operators to establish long-distance calls between toll offices. The first customer-dialed direct call using area codes was made on November 10, 1951, from Englewood, New Jersey, to Alameda, California. Direct distance dialing was subsequently introduced across the country.
By the early 1960s, most areas of the Bell System had been converted and DDD had become commonplace in cities and most larger towns. In the following decades, the system expanded to include all of the United States and its territories, Canada and seventeen nations of the Caribbean. By 1967, 129 area codes had been assigned. At the request of the British Colonial Office, the numbering plan was first expanded to Bermuda and the British West Indies because of their historic telecommunications administration through Canada as parts of the British Empire and their continued associations with Canada during the years of the telegraph and the All Red Line system. Not all North American countries participate in the NANP. Exceptions include Mexico, Saint Pierre and Miquelon, the Central American countries and some Caribbean countries; the only Spanish-speaking state in the system is the Dominican Republic. Mexican participation was planned, but implementation stopped after three area codes had been assigned, Mexico opted for an international numbering format, using country code 52.
The area codes in use were subsequently withdrawn in 1991. Area code 905 for Mexico City, was reassigned to a split of area code 416 in the Greater Toronto Area. Dutch-speaking Sint Maarten joined the NANP in September 2011, receiving area code 721; the NANP is administered by the North American Numbering Plan Administration. Today, this function is overseen by the Federal Communications Commission, which assumed the responsibility upon the breakup of the Bell System; the FCC solicits private sector contracts for the role of the administrator. The service was provided by a division of Lockheed Martin. In 1997, the contract was awarded to Neustar Inc.. In 2012, the contract was renewed until 2017. In 2015, the contract beginning 2017 was granted to Ericsson; the vision and goal of the architects of the North American Numbering Plan was a system by which telephone subscribers in the United States and Canada could themselves dial and establish a telephone call to any other subscriber wi
California is a state in the Pacific Region of the United States. With 39.6 million residents, California is the most populous U. S. the third-largest by area. The state capital is Sacramento; the Greater Los Angeles Area and the San Francisco Bay Area are the nation's second and fifth most populous urban regions, with 18.7 million and 9.7 million residents respectively. Los Angeles is California's most populous city, the country's second most populous, after New York City. California has the nation's most populous county, Los Angeles County, its largest county by area, San Bernardino County; the City and County of San Francisco is both the country's second-most densely populated major city after New York City and the fifth-most densely populated county, behind only four of the five New York City boroughs. California's $3.0 trillion economy is larger than that of any other state, larger than those of Texas and Florida combined, the largest sub-national economy in the world. If it were a country, California would be the 5th largest economy in the world, the 36th most populous as of 2017.
The Greater Los Angeles Area and the San Francisco Bay Area are the nation's second- and third-largest urban economies, after the New York metropolitan area. The San Francisco Bay Area PSA had the nation's highest GDP per capita in 2017 among large PSAs, is home to three of the world's ten largest companies by market capitalization and four of the world's ten richest people. California is considered a global trendsetter in popular culture, innovation and politics, it is considered the origin of the American film industry, the hippie counterculture, fast food, the Internet, the personal computer, among others. The San Francisco Bay Area and the Greater Los Angeles Area are seen as global centers of the technology and entertainment industries, respectively. California has a diverse economy: 58% of the state's economy is centered on finance, real estate services and professional, scientific and technical business services. Although it accounts for only 1.5% of the state's economy, California's agriculture industry has the highest output of any U.
S. state. California is bordered by Oregon to the north and Arizona to the east, the Mexican state of Baja California to the south; the state's diverse geography ranges from the Pacific Coast in the west to the Sierra Nevada mountain range in the east, from the redwood–Douglas fir forests in the northwest to the Mojave Desert in the southeast. The Central Valley, a major agricultural area, dominates the state's center. Although California is well-known for its warm Mediterranean climate, the large size of the state results in climates that vary from moist temperate rainforest in the north to arid desert in the interior, as well as snowy alpine in the mountains. Over time and wildfires have become more pervasive features. What is now California was first settled by various Native Californian tribes before being explored by a number of European expeditions during the 16th and 17th centuries; the Spanish Empire claimed it as part of Alta California in their New Spain colony. The area became a part of Mexico in 1821 following its successful war for independence but was ceded to the United States in 1848 after the Mexican–American War.
The western portion of Alta California was organized and admitted as the 31st state on September 9, 1850. The California Gold Rush starting in 1848 led to dramatic social and demographic changes, with large-scale emigration from the east and abroad with an accompanying economic boom; the word California referred to the Baja California Peninsula of Mexico. The name derived from the mythical island California in the fictional story of Queen Calafia, as recorded in a 1510 work The Adventures of Esplandián by Garci Rodríguez de Montalvo; this work was the fifth in a popular Spanish chivalric romance series that began with Amadis de Gaula. Queen Calafia's kingdom was said to be a remote land rich in gold and pearls, inhabited by beautiful black women who wore gold armor and lived like Amazons, as well as griffins and other strange beasts. In the fictional paradise, the ruler Queen Calafia fought alongside Muslims and her name may have been chosen to echo the title of a Muslim leader, the Caliph. It's possible.
Know ye that at the right hand of the Indies there is an island called California close to that part of the Terrestrial Paradise, inhabited by black women without a single man among them, they lived in the manner of Amazons. They were robust of body with great virtue; the island itself is one of the wildest in the world on account of the craggy rocks. Shortened forms of the state's name include CA, Cal. Calif. and US-CA. Settled by successive waves of arrivals during the last 10,000 years, California was one of the most culturally and linguistically diverse areas in pre-Columbian North America. Various estimates of the native population range from 100,000 to 300,000; the Indigenous peoples of California included more than 70 distinct groups of Native Americans, ranging from large, settled populations living on the coast to groups in the interior. California groups were diverse in their political organization with bands, villages, on the resource-rich coasts, large chiefdoms, such as the Chumash and Salinan.
Trade, intermarriage a
A census is the procedure of systematically acquiring and recording information about the members of a given population. The term is used in connection with national population and housing censuses; the United Nations defines the essential features of population and housing censuses as "individual enumeration, universality within a defined territory and defined periodicity", recommends that population censuses be taken at least every 10 years. United Nations recommendations cover census topics to be collected, official definitions and other useful information to co-ordinate international practice; the word is of Latin origin: during the Roman Republic, the census was a list that kept track of all adult males fit for military service. The modern census is essential to international comparisons of any kind of statistics, censuses collect data on many attributes of a population, not just how many people there are. Censuses began as the only method of collecting national demographic data, are now part of a larger system of different surveys.
Although population estimates remain an important function of a census, including the geographic distribution of the population, statistics can be produced about combinations of attributes e.g. education by age and sex in different regions. Current administrative data systems allow for other approaches to enumeration with the same level of detail but raise concerns about privacy and the possibility of biasing estimates. A census can be contrasted with sampling in which information is obtained only from a subset of a population. Modern census data are used for research, business marketing, planning, as a baseline for designing sample surveys by providing a sampling frame such as an address register. Census counts are necessary to adjust samples to be representative of a population by weighting them as is common in opinion polling. Stratification requires knowledge of the relative sizes of different population strata which can be derived from census enumerations. In some countries, the census provides the official counts used to apportion the number of elected representatives to regions.
In many cases, a chosen random sample can provide more accurate information than attempts to get a population census. A census is construed as the opposite of a sample as its intent is to count everyone in a population rather than a fraction. However, population censuses rely on a sampling frame to count the population; this is the only way to be sure that everyone has been included as otherwise those not responding would not be followed up on and individuals could be missed. The fundamental premise of a census is that the population is not known and a new estimate is to be made by the analysis of primary data; the use of a sampling frame is counterintuitive as it suggests that the population size is known. However, a census is used to collect attribute data on the individuals in the nation; this process of sampling marks the difference between historical census, a house to house process or the product of an imperial decree, the modern statistical project. The sampling frame used by census is always an address register.
Thus it is not known how many people there are in each household. Depending on the mode of enumeration, a form is sent to the householder, an enumerator calls, or administrative records for the dwelling are accessed; as a preliminary to the dispatch of forms, census workers will check any address problems on the ground. While it may seem straightforward to use the postal service file for this purpose, this can be out of date and some dwellings may contain a number of independent households. A particular problem is what are termed'communal establishments' which category includes student residences, religious orders, homes for the elderly, people in prisons etc; as these are not enumerated by a single householder, they are treated differently and visited by special teams of census workers to ensure they are classified appropriately. Individuals are counted within households and information is collected about the household structure and the housing. For this reason international documents refer to censuses of housing.
The census response is made by a household, indicating details of individuals resident there. An important aspect of census enumerations is determining which individuals can be counted from which cannot be counted. Broadly, three definitions can be used: de facto residence; this is important to consider individuals who have temporary addresses. Every person should be identified uniquely as resident in one place but where they happen to be on Census Day, their de facto residence, may not be the best place to count them. Where an individual uses services may be more useful and this is at their usual, or de jure, residence. An individual may be represented at a permanent address a family home for students or long term migrants, it is necessary to have a precise definition of residence to decide whether visitors to a country should be included in the population count. This is becoming more important as students travel abroad for education for a period of several years. Other groups causing problems of enumeration are new born babies, people away on holiday, people moving home around census day, people without a fixed address.
People having second homes because of working in another part of the country or retaining a holiday cottage are dif