Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Formula Predicts How People Will Migrate in Coming Decades

01.10.2008
Scientists at Rockefeller University, with assistance from the United Nations, have developed a predictive model of worldwide population shifts that they say will provide better estimates of migration across international boundaries.

Nearly 200 million people now live outside their country of birth. But the patterns of migration that got them there have proven difficult to project.

Now scientists at Rockefeller University, with assistance from the United Nations, have developed a predictive model of worldwide population shifts that they say will provide better estimates of migration across international boundaries. Because countries use population projections to estimate local needs for jobs, schools, housing and health care, a more precise formula to describe how people move could lead to better use of resources and improved economic conditions.

The model, published in the Sept. 29 online Early Edition of Proceedings of the National Academy of Sciences, improves existing ways to estimate population movement between individual countries and is being considered by the United Nations as an approach all nations can utilize, says the study's lead investigator, Joel E. Cohen, Abby Rockefeller Mauzé Professor and head of the Laboratory of Populations. "From year to year, it has been difficult to calculate how the world's population ebbs and flows between countries other than guessing that this year will resemble last year. But that is critical information in so many ways, and this model offers a new and unified approach that, we hope, will be of global benefit," Cohen says.

Formulas used until now were so flawed that they sometimes estimated that net emigration away from a particular country was greater than the country's original population, Cohen says, with a result that a nation was left with a predicted population of fewer than zero. "This has been a very inexact science," Cohen says.

To minimize such problems, Cohen and his colleagues used 43,653 reports from 11 countries of migration, which included 228 origins and 195 destinations reported from 1960 to 2004. The data on population and migration were provided by coauthor Marta Roig of the United Nations' Population Division. Cohen then added other geographical data. He and the other coauthors, Daniel Reuman, a former postdoctoral researcher at Rockefeller who is now at Imperial College London, and Cai GoGwilt, a Massachusetts Institute of Technology undergraduate who was a summer intern at Rockefeller, determined how to weight each variable.

The variables they selected were the populations and areas of countries receiving and sending people, the trend over time and the distance between locations. They then added "indicator" variables to account for differences in how nations report their data and used off-the-shelf computer software to estimate coefficients of a mathematical model of migration patterns.

"Our model accounts for roughly 60 percent of the variation in annual numbers of migrants from any country or region to any other, based on historical data, and nothing has come close to this," says Cohen. "This is only a first step, but it is a step that had not been made before. I hope this stimulates countries to come together and improve the standards by which they collect migration data. The data available to us are incomplete, inconsistent and in some cases contradictory. Better data in the future will help to improve models like this."

Understanding international migration has become more important in recent years because fertility worldwide has dropped, Cohen says. "That means the relative importance of migration as a factor in population change is accentuated, particularly for the countries that are the big receivers." For example, significant numbers of workers leave Southeast Asia for work in the Middle East, and migration continues from Turkey to Germany, Pakistan to England and Mexico to the United States.

The study was funded by a National Science Foundation award that supports Cohen's laboratory.

Joseph Bonner | Newswise Science News
Further information:
http://www.rockefeller.edu

Further reports about: Migrate Migration Population worldwide population

More articles from Social Sciences:

nachricht New measure for the wellbeing of populations could replace Human Development Index
07.11.2018 | International Institute for Applied Systems Analysis (IIASA)

nachricht Because not only arguments count
30.10.2018 | Max-Planck-Institut für Mathematik in den Naturwissenschaften (MPIMIS)

All articles from Social Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The geometry of an electron determined for the first time

Physicists at the University of Basel are able to show for the first time how a single electron looks in an artificial atom. A newly developed method enables them to show the probability of an electron being present in a space. This allows improved control of electron spins, which could serve as the smallest information unit in a future quantum computer. The experiments were published in Physical Review Letters and the related theory in Physical Review B.

The spin of an electron is a promising candidate for use as the smallest information unit (qubit) of a quantum computer. Controlling and switching this spin or...

Im Focus: Self-repairing batteries

UTokyo engineers develop a way to create high-capacity long-life batteries

Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...

Im Focus: Quantum Cloud Computing with Self-Check

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...

Im Focus: Accelerating quantum technologies with materials processing at the atomic scale

'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.

However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...

Im Focus: A step towards probabilistic computing

Working group led by physicist Professor Ulrich Nowak at the University of Konstanz, in collaboration with a team of physicists from Johannes Gutenberg University Mainz, demonstrates how skyrmions can be used for the computer concepts of the future

When it comes to performing a calculation destined to arrive at an exact result, humans are hopelessly inferior to the computer. In other areas, humans are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Plumbene, graphene's latest cousin, realized on the 'nano water cube'

23.05.2019 | Materials Sciences

New flatland material: Physicists obtain quasi-2D gold

23.05.2019 | Materials Sciences

New Boost for ToCoTronics

23.05.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>