This website was created, and is updated, by Gerhard K. Heilig

e-mail: gerhard.heilig@gmail.com

For most of my career I worked on issues related to global demographic change - particularly on questions of projecting population growth, population ageing, urbanization, economic development and environemental degradation.
In particular I was interested in the relations between population growth, land use change, food-security and economic development in China after Deng Xiaoping's reforms. During my time as a Senior Research Scholar at the International Institute for Applied Systems Analyses I conducted a major study on population and food security in China, titled: Can China feed itself.
I also worked on the chances of rural development to prevent further de-population of rural areas in Europe. I served as a Senior Researcher and Project Leader at the International Institute for Applied Systems Analysis (IIASA) for more than 17 years.

Im my last position before retirement, I was Chief of the Population Estimates and Projections Section at the Population Division of the United Nations Department of Economic and Social Affairs (DESA) from 2006 to 2013.

At the UN Population Division I led the team that prepared the official United Nations World Population Prospects and the World Urbanization Prospects. I was responsible for the publication of the 2006 Revision and the preparation and publication of the 2008 and 2010 Revisions of the World Population Prospects. I also led most of the preparation for the 2012 Revision, before I retired in February 2013. I also supervised, and contributed to, the preparation and publication of the 2007, 2009 and 2011 Revisions of the World Urbanization Prospects.

Under my leadership the Population Estimates and Projections Section of the Population Division introduced several new methods for population estimation and projection - most notably the first Probabilistic Population Projections for all countries of the world, published in 2012. For the high- and medium-fertility countries these projections are based on a Bayesian Hierarchical Model, which takes into account the empirical evidence of all fertility declines to calculate thousands of trajectories for the fertility decline of a particular country. This allows the calculation of confidence intervals for the projections. For details, please see the official website of the United Nations Population Division at:

http://esa.un.org/unpd/wpp/

I have also developed software and websites for many decades.