Estimated size of human population from 10,000 BCE–2000 CE.

Population growth is the change in a population over time, and can be quantified as the change in the number of individuals of any species in a population using "per unit time" for measurement. In biology, the term population growth is likely to refer to any known organism, but this article deals mostly with the application of the term to human populations in demography.

In demography, population growth is used informally for the more specific term population growth rate (see below), and is often used to refer specifically to the growth of the human population of the world.

Simple models of population growth include the Malthusian Growth Model and the logistic model.

Population growth 1800-2011: from 1 billion to 7 billion estimated in 31.10.2011. During the year 2011 according to estimates:^[1]

• 135 million people will be born
• 57 million people will die and
• 78 million people will increase the world population.

Determinants of population growth[link]

Population growth is determined by four factors, births(B), deaths(D), immigrants(I), and emigrants(E). Using a formula expressed as

∆P≡(B-D)+(I-E)

In other words, the population growth of a period can be calculated in two parts, natural growth of population (B-D) and mechanical growth of population (I-E),in which Mechanical growth of population is mainly affected by social factors, e.g. the advanced economies are growing faster while the backward economies are growing slowly even with negative growth.

Population growth rate[link]

In demographics and ecology, population growth rate (PGR) is the rate at which the number of individuals in a population increases in a given time period as a fraction of the initial population. Specifically, PGR ordinarily refers to the change in population over a unit time period, often expressed as a percentage of the number of individuals in the population at the beginning of that period. This can be written as the formula:^[2]

Failed to parse (Missing texvc executable; please see math/README to configure.): PGR = \frac{ \ln(P(t_2)) - \ln(P(t_1))} {(t_2-t_1)}

The most common way to express population growth is as a percentage, not as a rate. The change in population over a unit time period is expressed as a percentage of the population at the beginning of the time period. That is:

Failed to parse (Missing texvc executable; please see math/README to configure.): \mathrm{Percentage\ Growth} = \mathrm{Growth\ rate} \times 100%.

For small time periods and growth rates, the added population is the growth rate multiplied by the time period.

A positive growth ratio (or rate) indicates that the population is increasing, while a negative growth ratio indicates the population is decreasing. A growth ratio of zero indicates that there were the same number of people at the two times -- net difference between births, deaths a growth rate may be zero even when there are significant changes in the birth rates, death rates, immigration rates, and age distribution between the two times. ^[3] Equivalently, percent death rate = the average number of deaths in a year for every 100 people in the total population.

If the length of the time is taken smaller and smaller, the PGR approaches the logarithmic derivative of the population function P. If the population as a function of time is exponential, say P(t) = Ce^at, the logarithmic derivative is a. Thus, the PGR approximates the exponent a for populations with exponential growth.

A related measure is the net reproduction rate. In the absence of migration, a net reproduction rate of more than one indicates that the population of women is increasing, while a net reproduction rate less than one (sub-replacement fertility) indicates that the population of women is decreasing.

Excessive growth and decline[link]

Main articles: Overpopulation and population decline

Population exceeding the carrying capacity of an area or environment is called overpopulation. It may be caused by growth in population or by reduction in capacity. Spikes in human population can cause problems such as pollution and traffic congestion, these might be resolved or worsened by technological and economic changes. Conversely, such areas may be considered "underpopulated" if the population is not large enough to maintain an economic system (see population decline). Between these two extremes sits the notion of the optimum population.

Human population growth rate[link]

Annual population growth rate in percent, as listed in the CIA World Factbook (2011 estimate).^[4]

Growth rate of world population (1950-2050)

Population of the world from 10,000 BCE to 2000 CE (logarithmic scale)

Globally, the growth rate of the human population has been declining since peaking in 1962 and 1963 at 2.20% per annum. In 2009, the estimated annual growth rate was 1.1%.^[5] The CIA World Factbook gives the world annual birthrate, mortality rate, and growth rate as 1.915%, 0.812%, and 1.092% respectively^[6] The last one hundred years have seen a rapid increase in population due to medical advances and massive increase in agricultural productivity^[7] made possible by the Green Revolution.^[8][9][10]

The actual annual growth in the number of humans fell from its peak of 88.0 million in 1989, to a low of 73.9 million in 2003, after which it rose again to 75.2 million in 2006. Since then, annual growth has declined. In 2009, the human population increased by 74.6 million, which is projected to fall steadily to about 41 million per annum in 2050, at which time the population will have increased to about 9.2 billion.^[11] Each region of the globe has seen great reductions in growth rate in recent decades, though growth rates remain above 2% in some countries of the Middle East and Sub-Saharan Africa, and also in South Asia, Southeast Asia, and Latin America.^[12]

Some countries experience negative population growth, especially in Eastern Europe mainly due to low fertility rates, high death rates and emigration. In Southern Africa, growth is slowing due to the high number of HIV-related deaths. Some Western Europe countries might also encounter negative population growth.^[13] Japan's population began decreasing in 2005.^[14]

Growth by country[link]

According to United Nations population statistics, the world population grew by 30%, or 1.6 billion people, between 1990 and 2010.^[15] As persons the increase was among highest in India 350 million and China 196 million. Population growth was among highest in the United Arab Emirates (315%) and Qatar (271%).^[15]

Rank	Country	Population (thousands) 2010	Population (thousands) 1990	Growth (%) 1990-2010
	World	6,895,889	5,306,425	30.0%
1	China	1,341,335	1,145,195	17.1%
2	India	1,224,614	873,785	40.2%
3	United States	310,384	253,339	22.5%
4	Indonesia	239,871	184,346	30.1%
5	Brazil	194,946	149,650	30.3%
6	Pakistan	173,593	111,845	55.3%
7	Nigeria	158,423	97,552	62.4%
8	Bangladesh	148,692	105,256	41.3%
9	Russia	142,958	148,244	-3.6%
10	Japan	128,057	122,251	4.7%

1960s to 2010 table of population growth[link]

Many of the world's countries, including many in Sub-Saharan Africa, the Middle East, South Asia and South East Asia, have seen a sharp rise in population since the end of the Cold War. The fear is that high population numbers are putting further strain on natural resources, food supplies, fuel supplies, employment, housing, etc.; in some the less fortunate countries. The population of Chad has, for example, ultimately grown from 6,279,921 in 1993 to 10,329,208 in 2009,^[17] further straining its resources. Vietnam, Mexico, Nigeria, Egypt, Ethiopia and the DRC are witnessing a similar growth in population, strained resources and a possible overpopulation problem in the near future^{[citation needed]}.

The situation was most acute in northern, western and central Africa. Refugees from places like the Sudan have helped further strain the resources of neighbouring states like Chad and Egypt. The nation is also host to roughly 255,000 refugees from Sudan’s Darfur region, and about 77,000 refugees from the Central African Republic, whilst approximately 188,000 Chadians have been displaced by their own civil war and famines, have either fled to either the Sudan, the Niger or, more recently, Libya.

Notes

* Eritrea left Ethiopia in 1991.

** Split in to the nations of Sudan and Southern Sudan during 2011.

*** Merged in 1972.

# Merged in 1975.

Into the future[link]

According to projections, the world population will continue to grow until at least 2050, with the population reaching 9.1 billion in 2050.^[47]

See also[link]

References[link]

External links[link]

• 2008 Essays on Population Growth Blue Planet United — Population Press
• World population growth and trends 1950-2050 US Census
• UN University annual "State of the Future" report, including updates on Millennium Project goals including balancing global population growth & resources
• BBC News - Birth rate 'harms poverty goals' - 08/12/06
• Trend of growth rate with total global population
• Visual representation of global population and other statistics
• Tsirel, S. V. 2004. On the Possible Reasons for the Hyperexponential Growth of the Earth Population. Mathematical Modeling of Social and Economic Dynamics / Ed. by M. G. Dmitriev and A. P. Petrov, pp. 367–9. Moscow: Russian State Social University, 2004.
• Rosling, Hans (25 January 2009). "What stops population growth?". Gapminder. http://www.gapminder.org/videos/what-stops-population-growth/. Retrieved 2009-07-06. 

Hans Rosling
Rosling at the 2012 Time 100 gala
Born	(1948-07-27) July 27, 1948 (age 63)
Institutions	Karolinska Institute
Alma mater	Uppsala University, St. John's Medical College
Known for	Gapminder Foundation and Trendalyzer

Hans Rosling (born 27 July 1948^[1] in Uppsala, Sweden) is a Swedish medical doctor, academic, statistician and public speaker. He is Professor of International Health at Karolinska Institute^[2] and co-founder and chairman of the Gapminder Foundation, which developed the Trendalyzer software system.

Study and career[link]

From 1967 to 1974 Rosling studied statistics and medicine at Uppsala University, and in 1972 he studied public health at St. John's Medical College, Bangalore. He became a licenced physician in 1976 and from 1979 to 1981 he served as District Medical Officer in Nacala in northern Mozambique.

On 21 August 1981, Rosling discovered an outbreak of konzo, a paralytic disease,^[3][4] and the investigations that followed earned him a Ph.D. degree at Uppsala University in 1986. He spent two decades studying outbreaks of this disease in remote rural areas across Africa and supervised more than ten Ph.D. students^{[citation needed]}. Outbreaks occur among hunger-stricken rural populations in Africa where a diet dominated by insufficiently processed cassava results in simultaneous malnutrition and high dietary cyanide intake.^[4]

Rosling's research has also focused on other links between economic development, agriculture, poverty and health^[5] in Africa, Asia and Latin America. He has been health adviser to WHO, UNICEF and several aid agencies. In 1993 he was one of the initiators of Médecins Sans Frontières in Sweden. At Karolinska Institutet he was head of the Division of International Health (IHCAR) from 2001 to 2007. As chairman of Karolinska International Research and Training Committee (1998–2004) he started health research collaborations with universities in Asia, Africa, the Middle East and Latin America. He started new courses on Global Health and co-authored a textbook on Global Health that promotes a fact-based world view.

Rosling presented the television documentary The Joy of Stats, which was broadcast in the United Kingdom by BBC Four in December 2010.^[6]

Gapminder[link]

Rosling co-founded the Gapminder Foundation together with his son Ola Rosling and daughter-in-law Anna Rosling Rönnlund. Gapminder developed the Trendalyzer software that converts international statistics into moving, interactive graphics. His lectures using Gapminder graphics to visualise world development have won awards.^[7] The interactive animations are freely available from the Foundation's website. On 16 March 2007 Google acquired the Trendalyzer software with the intention to scale it up and make it freely available for public statistics. In 2008 Google made available a Motion Chart Google Gadget and in 2009 the Public Data Explorer.^[8]

Rosling is also a sword swallower, as demonstrated in the final moments of his second talk at the TED conference.^[9] In 2009 he was listed as one of 100 leading global thinkers by Foreign Policy Magazine,^[10] and in 2011 as one of 100 most creative people in business by the Fast Company Magazine.^[11] In 2011 he was elected member of the Swedish Academy of Engineering Sciences.

Awards[link]

Hans Rosling at the Swedish pavilion of Expo 2010 in Shanghai

• 2007 – Statistician of the Year Award from the Swedish Association for Statistics
• 2007 – Jubilee Prize from the Swedish Medical Society
• 2007 – Knowledge Prize from the National Encyclopaedia of Sweden
• 2008 – Speaker of the Year from the Swedish Event Academy
• 2008 – The Big Debate Award from Dagens Medicine
• 2009 – Georg and Greta Borgstrom Award from the Swedish Royal Academy of Agriculture and Forestry
• 2010 – Illis Quorum, Highest Award conferred by the Government of Sweden
• 2010 – The Grand Prize from the Royal Institute of Technology, Stockholm, Sweden
• 2010 – Gold Medal from Royal Swedish Academy of Engineering Sciences
• 2010 – World Technology Award in Design together with Ola Rosling & Anna Rosling Rönnlund
• 2010 – The Gannon Award for the Continued Pursuit of Human Advancement (US)^[12]
• 2011 - Grierson 2011 Award for the Best British Science Documentary, presenter in "The Joy of Stats"
• 2012 - Time 100 most influential people list

Selected publications[link]

• Thorson, A.; Ragnarsson, A.; Rosling, H.; Ekström, A. (2010). "Male circumcision reduces HIV transmission. The risk of transmission from woman to man is halved". Lakartidningen 107 (46): 2881–2883. PMID 21197783.  edit
• Hanson, S.; Thorson, A.; Rosling, H.; Örtendahl, C.; Hanson, C.; Killewo, J.; Ekström, A. M. (2009). Husereau, Don. ed. "Estimating the Capacity for ART Provision in Tanzania with the Use of Data on Staff Productivity and Patient Losses". PLoS ONE 4 (4): e5294. DOI:10.1371/journal.pone.0005294. PMC 2667213. PMID 19381270. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2667213.  edit
• Von Schreeb, J.; Riddez, L.; Samnegård, H.; Rosling, H. (2008). "Foreign field hospitals in the recent sudden-onset disasters in Iran, Haiti, Indonesia, and Pakistan". Prehospital and disaster medicine : the official journal of the National Association of EMS Physicians and the World Association for Emergency and Disaster Medicine in association with the Acute Care Foundation 23 (2): 144–151; discussion 151–3. PMID 18557294.  edit
• Schell, C. O.; Reilly, M.; Rosling, H.; Peterson, S.; Ekström, A. M. (2007). "Socioeconomic determinants of infant mortality: A worldwide study of 152 low-, middle-, and high-income countries". Scandinavian Journal of Public Health 35 (3): 288–297. DOI:10.1080/14034940600979171. PMID 17530551.  edit
• Von Schreeb, J.; Rosling, H.; Garfield, R. (2007). "Mortality in Iraq". The Lancet 369 (9556): 101. DOI:10.1016/S0140-6736(07)60058-0. PMID 17223462.  edit
• Elrayah, H.; Eltom, M.; Bedri, A.; Belal, A.; Rosling, H.; Ostenson, C. (2005). "Economic burden on families of childhood type 1 diabetes in urban Sudan". Diabetes Research and Clinical Practice 70 (2): 159–165. DOI:10.1016/j.diabres.2005.03.034. PMID 15919129.  edit
• Thanh, H. T. T.; Jiang, G. X.; Van, T. N.; Minh, D. P. T.; Rosling, H.; Wasserman, D. (2005). "Attempted suicide in Hanoi, Vietnam". Social Psychiatry and Psychiatric Epidemiology 40 (1): 64–71. DOI:10.1007/s00127-005-0849-6. PMID 15624077.  edit
• Rosling, H. (2004). "New map of world health is needed. North and South is changed to healthy and ill and West to rich and poor". Lakartidningen 101 (3): 198–201. PMID 14763091.  edit

References[link]

Wikiquote has a collection of quotations related to: Hans Rosling

External links[link]

• Hans Rosling on Twitter
• Hans Rosling shows the best stats you've ever seen at the 2006 TED Conference in Monterey, CA highlighting novel ways of presenting global statistics.
• Hans Rosling's new insights on poverty, from TED2007, featuring a surprise ending. (video)
• Video of Hans Rosling speech at the OECD World Forum in Istanbul
• Hans Rosling's blog
• Ola Rosling giving a Gapminder presentation at Google (video)
• Motion Chart Google Gadget
• Hans Rosling: Global health expert; data visionary profile on TED.com

Steven E. Landsburg (b. February 24, 1954) is an American professor of economics at the University of Rochester in Rochester, New York. From 1989 to 1995, he taught at Colorado State University.

Education[link]

Landsburg was an undergraduate at the University of Rochester, but never completed his undergraduate requirements due to his failure to take a physical education course. He was awarded a Masters degree after he enrolled in his own course when he became a professor at the school^{[citation needed]}. Landsburg received a PhD in mathematics from the University of Chicago in 1979.

He also spent time at the Institute for Advanced Study in Princeton.^[1][2]

Writings and work[link]

Popular writings[link]

Steven E. Landsburg speaking at Warwick Economics Summit 2012

Landsburg wrote a column on "everyday economics" for Slate magazine from 1996 to 2008.^[3] The subjects of the columns were diverse and often drew on current affairs. In them, Landsburg discussed the national debt, the obesity crisis, payments to Hurricane Katrina evacuees in New Orleans and salary caps in the NFL. Landsburg also discussed recent research in micro-economics and its implications, as in an article on the value of mobile phones and driving, the (career) cost of motherhood, and whether or not daughters (as opposed to sons) cause divorce.

Landsburg also addressed legal issues: in a Slate column from 2003, he proposed punishing jurors when a jury's decision is later "proven" to be wrong, such as when an acquitted defendant later admits to committing the crime. If a jury's judgement is later "proven" to be right, Landsburg suggested the jurors should be financially rewarded.^[4]

Landsburg has been particularly critical of mainstream environmentalism having devoted both Slate columns and book chapters (in The Armchair Economist) to attack environmentalist principles. As a self-described "hardcore libertarian", Landsburg emphasizes the importance of individual choice.^[5] This position extends to health care, and his view that those who choose no insurance should not receive (potentially life saving) treatment.^[6] This position was asserted partly as a response to an article published by Daily Kos .

Landsburg supports free trade and opposes protectionism, and his writings in the topic have appeared in various newspapers and magazines, including the New York Times^[7] and the Washington Post. Landsburg's comparison of protectionism to racism in Forbes magazine^[8] prompted a response from Pat Buchanan.^[9] On April 8, 2005, Landsburg debated protectionism and free trade with John Gibson on the Fox News Channel's The Big Story.^[10] Before the 2004 presidential election Landsburg stated that he planned to vote against John Kerry because of his belief that John Edwards, Kerry's running mate, was a "xenophobe" due to his opposition to free trade. He compared Edwards' views to David Duke's racism.^[11]

He has also reviewed popular economics books Freakonomics^[12] and The Undercover Economist^[13] for the Wall Street Journal.

Landsburg has spoken at many distinguished events and in February 2012 he spoke at Warwick Economics Summit and the Adam Smith Institute in the United Kingdom.

In March 2012, Landsburg supported some of pop radio personality Rush Limbaugh's arguments against a Georgetown University student, Sandra Fluke's advocacy.^[14]. Fluke spoke before a congressional Democrats on mandating birth control coverage in some insurance programs citing their use in preventing ovarian cysts. "There are really good arguments for subsidizing and bad arguments for subsidizing [birth control]," Landsburg said during an interview with 13WHAM. "However, [Fluke] didn't bother to make any. She made no argument. She simply said she wanted it subsidized."^[15] On his blog, Landsburg discussed Limbaugh's calling Fluke a slut, and said "A far better word might have been “prostitute” (or a five-letter synonym therefor), but that’s still wrong because Ms. Fluke is not in fact demanding to be paid for sex...The right word for that is something much closer to “extortionist”."^[16] Langsburg's comments drew a rebuke from University of Rochester President Joel Seligman, who said he was "outraged that any professor would demean a student in this fashion", and a silent protest from thirty UR students who formed a line between him and his students during one of his classes.^[17]

Academic writings[link]

Landsburg's articles in academic journals have dealt with many fields, including algebraic K-theory, module patching, quantum game theory^{[citation needed]}, philosophy of science and, moral philosophy.

Selected publications follow.

Mathematics[link]

• K-theory and patching for categories of complexes, Duke Mathematics Journal, Vol. 62, No. 2, March 1991, pp. 359–384.
• Relative Cycles and Algebraic K-Theory, American Journal of Mathematics, Vol. 111, No. 4, August 1989, pp. 599–632.

Teaching[link]

Landsburg teaches intermediate and advanced microeconomics at the University of Rochester.^[18] He was promoted from adjunct associate professor to professor during the 2005-2006 academic year and in 2007 he received the University's Professor of the Year in Social Sciences award.^[19]

Personal[link]

For several years, Landsburg served on the board of directors of Hutchinson Technology, a manufacturer of suspension assemblies for disk drives.

Landsburg lives in Rochester, NY. In his spare time he reads poetry and enjoys crossword puzzles. He has one daughter, named Cayley, who was featured in his book Fair Play.

He has eastern European Jewish heritage.^[20]

Books[link]

• Price Theory and Applications (1989)
• The Armchair Economist (1993)
• Macroeconomics (1996)
• Fair Play (1997)
• More Sex is Safer Sex, The Unconventional Wisdom of Economics (2007)
• The Big Questions: Tackling the Problems of Philosophy with Ideas from Mathematics, Economics and Physics (2009)
• A Mathematical Introduction to General Relativity and Cosmology (unreleased)

References[link]

1. ^ Andre Weil: 1906-1998
2. ^ Andre Weil by Steven E
3. ^ Articles By Steven E. Landsburg
4. ^ Should we punish juries that get it wrong?
5. ^ The Volokh Conspiracy
6. ^ Do the poor deserve life support? - By Steven E. Landsburg - Slate Magazine
7. ^ What to Expect When You’re Free Trading - New York Times
8. ^ Xenophobia and Politics - Forbes.com
9. ^ Is Protectionism Racism?
10. ^ FOXNews.com - Is Buying American Racist? - John Gibson | Judge Napolitano | John Gibson | Big Story Weekend
11. ^ Slate votes. - - Slate Magazine
12. ^ The Wall Street Journal Online - Leisure & Arts
13. ^ The Wall Street Journal Online - Leisure & Arts
14. ^ http://www.thebigquestions.com/2012/03/02/rush-to-judgment/
15. ^ http://www.13wham.com/news/local/story/Local-Professor-Backs-Controversial-Limbaugh/2mnZkNH2g0Kvi8WXecW6Rw.cspx
16. ^ "Rush to Judgment", 2 Mar 2012[1]
17. ^ http://www.democratandchronicle.com/article/20120307/NEWS01/303070022/University-of-Rochester-Rush-Limbaugh-Steven-Landsburg
18. ^ Class Description Lookup
19. ^ Professor of the Year recipients honored - News
20. ^ http://slate.msn.com/id/2084352/

External links[link]

• About Professor Landsburg via University of Rochester
• Steven Landsburg's personal webpage
• The Big Questions Blog
• Landsburg's column at Slate
• Price Theory and Applications
• City News Interview of Landsburg: Part One, Part Two
• New York Times review of More Sex Is Safer Sex