State Space Models

All state space models are written and estimated in the R programming language. The models are available here with instructions and R procedures for manipulating the models here here.

Monday, June 1, 2015

Population Bomb: Forecast Gone Wrong?


Today the New York Times published a Retro Report titled The Unrealized Horrors of Population Explosion accompanied by the video above. The report takes a look at predictions made by American biologist Paul Ehrlich in his 1968 book The Population Bomb. In the book, Ehrlich presented future scenarios (he clearly stated they weren't predictions) that, for example, by 1970 hundreds of millions of people would starve from population growth increasing faster than food production (basically a restatement of the Malthusian Catastrophe). It didn't happen and, regardless of Ehrlich's protestations, his "predictions" have come to be viewed as notorious examples of forecasts that proved wrong. But more is at stake here than Ehrlich's forecasting ability.

Population growth is the primary exogenous forcing variable in the IPCC Emission Scenarios, in Limits to Growth Models and in Neoclassical Economic Growth Models that do not recognize any limit to growth (see my discussion here). If Ehrlich's predictions were wrong does that mean that there are no limits to growth and that we don't have to worry about CO2 emissions? I'll let you watch the video, read the New York Times article, follow the other links and think about this question.

In future posts, I'll make my own forecasts for World population and look at what some of the consequences might be.