Population density is a measurement of population per unit area or unit volume. It is applied to living organisms, most of the time to humans, it is a key geographical term. In simple terms population density refers to the number of people living in an area per kilometer square. Population density is population divided by total land water volume, as appropriate. Low densities may lead to further reduced fertility; this is called the Allee effect after the scientist. Examples of the causes in low population densities include: Increased problems with locating sexual mates Increased inbreeding For humans, population density is the number of people per unit of area quoted per square kilometer or square mile; this may be calculated for a county, country, another territory or the entire world. The world's population is around 7,500,000,000 and Earth's total area is 510,000,000 square kilometers. Therefore, the worldwide human population density is around 7,500,000,000 ÷ 510,000,000 = 14.7 per km2. If only the Earth's land area of 150,000,000 km2 is taken into account human population density is 50 per km2.
This includes all continental and island land area, including Antarctica. If Antarctica is excluded population density rises to over 55 people per km2. However, over half of the Earth's land mass consists of areas inhospitable to human habitation, such as deserts and high mountains, population tends to cluster around seaports and fresh-water sources. Thus, this number by itself does not give any helpful measurement of human population density. Several of the most densely populated territories in the world are city-states and dependencies; these territories have a small area and a high urbanization level, with an economically specialized city population drawing on rural resources outside the area, illustrating the difference between high population density and overpopulation The potential to maintain the agricultural aspects of deserts is limited as there is not enough precipitation to support a sustainable land. The population in these areas are low. Therefore, cities in the Middle East, such as Dubai, have been increasing in population and infrastructure growth at a fast pace.
Cities with high population densities are, by some, considered to be overpopulated, though this will depend on factors like quality of housing and infrastructure and access to resources. Most of the most densely populated cities are in Southeast Asia, though Cairo and Lagos in Africa fall into this category. City population and area are, however dependent on the definition of "urban area" used: densities are invariably higher for the central city area than when suburban settlements and the intervening rural areas are included, as in the areas of agglomeration or metropolitan area, the latter sometimes including neighboring cities. For instance, Milwaukee has a greater population density when just the inner city is measured, the surrounding suburbs excluded. In comparison, based on a world population of seven billion, the world's inhabitants, as a loose crowd taking up ten square feet per person, would occupy a space a little larger than Delaware's land area; the Gaza Strip has a population density of 5,046 pop/km.
Although arithmetic density is the most common way of measuring population density, several other methods have been developed to provide a more accurate measure of population density over a specific area. Arithmetic density: The total number of people / area of land Physiological density: The total population / area of arable land Agricultural density: The total rural population / area of arable land Residential density: The number of people living in an urban area / area of residential land Urban density: The number of people inhabiting an urban area / total area of urban land Ecological optimum: The density of population that can be supported by the natural resources Demography Human geography Idealized population Optimum population Population genetics Population health Population momentum Population pyramid Rural transport problem Small population size Distance sampling List of population concern organizations List of countries by population density List of cities by population density List of city districts by population density List of English districts by population density List of European cities proper by population density List of United States cities by population density List of islands by population density List of U.
S. states by population density List of Australian suburbs by population density Selected Current and Historic City, Ward & Neighborhood Density Duncan Smith / UCL Centre for Advanced Spatial Analysis. "World Population Density". Exploratory map shows data from the Global Human Settlement Layer produced by the European Commission JRC and the CIESIN Columbia University
1940 United States Census
The Sixteenth United States Census, conducted by the Census Bureau, determined the resident population of the United States to be 132,164,569, an increase of 7.3 percent over the 1930 population of 123,202,624 people. The census date of record was April 1, 1940. A number of new questions were asked including where people were 5 years before, highest educational grade achieved, information about wages; this census introduced sampling techniques. Other innovations included a field test of the census in 1939; this was the first census in which every state had a population greater than 100,000. The 1940 census collected the following information: In addition, a sample of individuals were asked additional questions covering age at first marriage and other topics. Full documentation on the 1940 census, including census forms and a procedural history, is available from the Integrated Public Use Microdata Series. Following completion of the census, the original enumeration sheets were microfilmed; as required by Title 13 of the U.
S. Code, access to identifiable information from census records was restricted for 72 years. Non-personally identifiable information Microdata from the 1940 census is available through the Integrated Public Use Microdata Series. Aggregate data for small areas, together with electronic boundary files, can be downloaded from the National Historical Geographic Information System. On April 2, 2012—72 years after the census was taken—microfilmed images of the 1940 census enumeration sheets were released to the public by the National Archives and Records Administration; the records are indexed only by enumeration district upon initial release. Official 1940 census website 1940 Census Records from the U. S. National Archives and Records Administration 1940 Federal Population Census Videos, training videos for enumerators at the U. S. National Archives Selected Historical Decennial Census Population and Housing Counts from the U. S. Census Bureau Snow, Michael S. "Why the huge interest in the 1940 Census?"
CNN. Monday April 9, 2012. 1941 U. S Census Report Contains 1940 Census results 1940 Census Questions Hosted at CensusFinder.com
Per capita income
Per capita income or average income measures the average income earned per person in a given area in a specified year. It is calculated by dividing the area's total income by its total population. Per capita income is national income divided by population size. Per capita income is used to measure an area's average income and compare the wealth of different populations. Per capita income is used to measure a country's standard of living, it is expressed in terms of a used international currency such as the euro or United States dollar, is useful because it is known, is calculable from available gross domestic product and population estimates, produces a useful statistic for comparison of wealth between sovereign territories. This helps to ascertain a country's development status, it is one of the three measures for calculating the Human Development Index of a country. In the United States, it is defined by the U. S. Census Bureau as the following: "Per capita income is the mean money income received in the past 12 months computed for every man and child in a geographic area."
Critics claim that per capita income has several weaknesses in measuring prosperity: Comparisons of per capita income over time need to consider inflation. Without adjusting for inflation, figures tend to overstate the effects of economic growth. International comparisons can be distorted by cost of living differences not reflected in exchange rates. Where the objective is to compare living standards between countries, adjusting for differences in purchasing power parity will more reflect what people are able to buy with their money, it does not reflect income distribution. If a country's income distribution is skewed, a small wealthy class can increase per capita income while the majority of the population has no change in income. In this respect, median income is more useful when measuring of prosperity than per capita income, as it is less influenced by outliers. Non-monetary activity, such as barter or services provided within the family, is not counted; the importance of these services varies among economies.
Per capita income does not consider whether income is invested in factors to improve the area's development, such as health, education, or infrastructure. List of countries by average wage List of countries by GDP per capita—GDP at market or government official exchange rates per inhabitant List of countries by GDP per capita—GDP calculated at purchasing power parity exchange per inhabitant List of countries by GNI per capita List of countries by GNI per capita List of countries by income equality Total personal income
Race and ethnicity in the United States Census
Race and ethnicity in the United States Census, defined by the federal Office of Management and Budget and the United States Census Bureau, are self-identification data items in which residents choose the race or races with which they most identify, indicate whether or not they are of Hispanic or Latino origin. The racial categories represent a social-political construct for the race or races that respondents consider themselves to be and, "generally reflect a social definition of race recognized in this country." OMB defines the concept of race as outlined for the US Census as not "scientific or anthropological" and takes into account "social and cultural characteristics as well as ancestry", using "appropriate scientific methodologies" that are not "primarily biological or genetic in reference." The race categories include both national-origin groups. Race and ethnicity are considered separate and distinct identities, with Hispanic or Latino origin asked as a separate question. Thus, in addition to their race or races, all respondents are categorized by membership in one of two ethnic categories, which are "Hispanic or Latino" and "Not Hispanic or Latino".
However, the practice of separating "race" and "ethnicity" as different categories has been criticized both by the American Anthropological Association and members of US Commission on Civil Rights. In 1997, OMB issued a Federal Register notice regarding revisions to the standards for the classification of federal data on race and ethnicity. OMB developed race and ethnic standards in order to provide "consistent data on race and ethnicity throughout the Federal Government; the development of the data standards stem in large measure from new responsibilities to enforce civil rights laws." Among the changes, OMB issued the instruction to "mark one or more races" after noting evidence of increasing numbers of interracial children and wanting to capture the diversity in a measurable way and having received requests by people who wanted to be able to acknowledge their or their children's full ancestry rather than identifying with only one group. Prior to this decision, the Census and other government data collections asked people to report only one race.
The OMB states, "many federal programs are put into effect based on the race data obtained from the decennial census. Race data are critical for the basic research behind many policy decisions. States require these data to meet legislative redistricting requirements; the data are needed to monitor compliance with the Voting Rights Act by local jurisdictions". "Data on ethnic groups are important for putting into effect a number of federal statutes. Data on Ethnic Groups are needed by local governments to run programs and meet legislative requirements." The 1790 United States Census was the first census in the history of the United States. The population of the United States was recorded as 3,929,214 as of Census Day, August 2, 1790, as mandated by Article I, Section 2 of the United States Constitution and applicable laws."The law required that every household be visited, that completed census schedules be posted in'two of the most public places within, there to remain for the inspection of all concerned...' and that'the aggregate amount of each description of persons' for every district be transmitted to the president."
This law along with U. S. marshals were responsible for governing the census. One third of the original census data has been lost or destroyed since documentation; the data was lost in 1790–1830 time period and included data from: Connecticut, Maryland, New Hampshire, New York, North Carolina, Rhode Island, South Carolina, Delaware, New Jersey, Virginia. Census data included the name of the head of the family and categorized inhabitants as follows: free white males at least 16 years of age, free white males under 16 years of age, free white females, all other free persons, slaves. Thomas Jefferson the Secretary of State, directed marshals to collect data from all thirteen states, from the Southwest Territory; the census was not conducted in Vermont until 1791, after that state's admission to the Union as the 14th state on March 4 of that year. There was some doubt surrounding the numbers, President George Washington and Thomas Jefferson maintained the population was undercounted; the potential reasons Washington and Jefferson may have thought this could be refusal to participate, poor public transportation and roads, spread out population, restraints of current technology.
No microdata from the 1790 population census is available, but aggregate data for small areas and their compatible cartographic boundary files, can be downloaded from the National Historical Geographic Information System. In 1800 and 1810, the age question regarding free white males was more detailed; the 1820
United States Census Bureau
The United States Census Bureau is a principal agency of the U. S. Federal Statistical System, responsible for producing data about the American people and economy; the Census Bureau is part of the U. S. Department of Commerce and its director is appointed by the President of the United States; the Census Bureau's primary mission is conducting the U. S. Census every ten years, which allocates the seats of the U. S. House of Representatives to the states based on their population; the Bureau's various censuses and surveys help allocate over $400 billion in federal funds every year and it helps states, local communities, businesses make informed decisions. The information provided by the census informs decisions on where to build and maintain schools, transportation infrastructure, police and fire departments. In addition to the decennial census, the Census Bureau continually conducts dozens of other censuses and surveys, including the American Community Survey, the U. S. Economic Census, the Current Population Survey.
Furthermore and foreign trade indicators released by the federal government contain data produced by the Census Bureau. Article One of the United States Constitution directs the population be enumerated at least once every ten years and the resulting counts used to set the number of members from each state in the House of Representatives and, by extension, in the Electoral College; the Census Bureau now conducts a full population count every 10 years in years ending with a zero and uses the term "decennial" to describe the operation. Between censuses, the Census Bureau makes population projections. In addition, Census data directly affects how more than $400 billion per year in federal and state funding is allocated to communities for neighborhood improvements, public health, education and more; the Census Bureau is mandated with fulfilling these obligations: the collecting of statistics about the nation, its people, economy. The Census Bureau's legal authority is codified in Title 13 of the United States Code.
The Census Bureau conducts surveys on behalf of various federal government and local government agencies on topics such as employment, health, consumer expenditures, housing. Within the bureau, these are known as "demographic surveys" and are conducted perpetually between and during decennial population counts; the Census Bureau conducts economic surveys of manufacturing, retail and other establishments and of domestic governments. Between 1790 and 1840, the census was taken by marshals of the judicial districts; the Census Act of 1840 established a central office. Several acts followed that revised and authorized new censuses at the 10-year intervals. In 1902, the temporary Census Office was moved under the Department of Interior, in 1903 it was renamed the Census Bureau under the new Department of Commerce and Labor; the department was intended to consolidate overlapping statistical agencies, but Census Bureau officials were hindered by their subordinate role in the department. An act in 1920 changed the date and authorized manufacturing censuses every two years and agriculture censuses every 10 years.
In 1929, a bill was passed mandating the House of Representatives be reapportioned based on the results of the 1930 Census. In 1954, various acts were codified into Title 13 of the US Code. By law, the Census Bureau must count everyone and submit state population totals to the U. S. President by December 31 of any year ending in a zero. States within the Union receive the results in the spring of the following year; the United States Census Bureau defines four statistical regions, with nine divisions. The Census Bureau regions are "widely used...for data collection and analysis". The Census Bureau definition is pervasive. Regional divisions used by the United States Census Bureau: Region 1: Northeast Division 1: New England Division 2: Mid-Atlantic Region 2: Midwest Division 3: East North Central Division 4: West North Central Region 3: South Division 5: South Atlantic Division 6: East South Central Division 7: West South Central Region 4: West Division 8: Mountain Division 9: Pacific Many federal, state and tribal governments use census data to: Decide the location of new housing and public facilities, Examine the demographic characteristics of communities and the US, Plan transportation systems and roadways, Determine quotas and creation of police and fire precincts, Create localized areas for elections, utilities, etc.
Gathers population information every 10 years The United States Census Bureau is committed to confidentiality, guarantees non-disclosure of any addresses or personal information related to individuals or establishments. Title 13 of the U. S. Code establishes penalties for the disclosure of this information. All Census employees must sign an affidavit of non-disclosure prior to employment; the Bureau cannot share responses, addresses or personal information with anyone including United States or foreign government
Barnwell County, South Carolina
Barnwell County is a county in the U. S. state of South Carolina. As of the 2010 census, its population was 22,621, its county seat is Barnwell. The Barnwell District was created in 1797 from the southwestern portion of the Orangeburg District, along the Savannah River, it was named after a local figure in the Revolutionary War. In 1868, under the South Carolina Constitution revised during Reconstruction, South Carolina districts became counties; the government was made more democratic, with county officials to be elected by male citizens at least 21 years old, rather than by the state legislature as done previously. In 1871 the legislature took the northwestern portion of the county to form part of the new Aiken County, the only county organized during the Reconstruction era. In 1874 the border with Aiken County was adjusted slightly; this county and Barnwell, with populations of blacks and whites that were nearly equal, had extensive violence in the months before the 1874 and 1876 elections, as groups of paramilitary Red Shirts rode to disrupt black Republican meetings and intimidate voters to suppress black voting.
More than 100 black men were killed in Aiken County during the violence at Ellenton, South Carolina. In 1895 white Democrats in the state legislature passed a new constitution, disfranchising most blacks for more than 60 years by raising barriers to voter registration. In 1897 the eastern third of the county was taken to form the new Bamberg County. In 1919 most of the southern half of the county was taken to form most of the new Allendale County, thus reducing Barnwell county to its present size. According to the U. S. Census Bureau, the county has a total area of 557 square miles, of which 548 square miles is land and 8.9 square miles is water. Aiken County - north Bamberg County - east Orangeburg County - east Allendale County - southeast Burke County, Georgia - southwest As of the census of 2000, there were 23,478 people, 9,021 households, 6,431 families residing in the county; the population density was 43 people per square mile. There were 10,191 housing units at an average density of 19 per square mile.
The racial makeup of the county was 55.18% White, 42.55% Black or African American, 0.35% Native American, 0.39% Asian, 0.03% Pacific Islander, 0.78% from other races, 0.72% from two or more races. 1.39% of the population were Hispanic or Latino of any race. There were 9,021 households out of which 34.80% had children under the age of 18 living with them, 47.40% were married couples living together, 19.30% had a female householder with no husband present, 28.70% were non-families. 25.60% of all households were made up of individuals and 10.20% had someone living alone, 65 years of age or older. The average household size was 2.57 and the average family size was 3.08. In the county, the population was spread out with 28.10% under the age of 18, 8.70% from 18 to 24, 27.90% from 25 to 44, 22.60% from 45 to 64, 12.60% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 92.70 males. For every 100 females age 18 and over, there were 86.50 males. The median income for a household in the county was $28,591, the median income for a family was $35,866.
Males had a median income of $31,161 versus $21,904 for females. The per capita income for the county was $15,870. About 17.90% of families and 20.90% of the population were below the poverty line, including 27.30% of those under age 18 and 24.40% of those age 65 or over. As of the 2010 United States Census, there were 22,621 people, 8,937 households, 6,055 families residing in the county; the population density was 41.2 inhabitants per square mile. There were 10,484 housing units at an average density of 19.1 per square mile. The racial makeup of the county was 52.6% white, 44.3% black or African American, 0.6% Asian, 0.4% American Indian, 0.7% from other races, 1.5% from two or more races. Those of Hispanic or Latino origin made up 1.8% of the population. In terms of ancestry, 11.5% were American, 5.7% were German, 5.4% were English. Of the 8,937 households, 34.0% had children under the age of 18 living with them, 41.8% were married couples living together, 20.8% had a female householder with no husband present, 32.2% were non-families, 28.4% of all households were made up of individuals.
The average household size was 2.50 and the average family size was 3.05. The median age was 38.8 years. The median income for a household in the county was $33,816 and the median income for a family was $41,764. Males had a median income of $35,957 versus $30,291 for females; the per capita income for the county was $17,592. About 20.8% of families and 25.4% of the population were below the poverty line, including 39.6% of those under age 18 and 11.5% of those age 65 or over. Barnwell Blackville Elko Hilda Kline Snelling Williston Rosa Louise Woodberry, school founder National Register of Historic Places listings in Barnwell County, South Carolina Barnwell County The Barnwell Web Geographic data related to Barnwell County, South Carolina at OpenStreetMap Barnwell County history and images
The Ashley-Willis House, located in the town of Williston, South Carolina is a notable as one of the few intact, gable-front Greek Revival residences in the state. It was listed in the National Register of Historic Places on June 22, 2004