Talk:Zero population growth

Fair use rationale for Image:Pyat rublei 1997.jpg

Image:Pyat rublei 1997.jpg is being used on this article. I notice the image page specifies that the image is being used under fair use but there is no explanation or rationale as to why its use in this Wikipedia article constitutes fair use. In addition to the boilerplate fair use template, you must also write out on the image description page a specific explanation or rationale for why using this image in each article is consistent with fair use.

Please go to the image description page and edit it to include a fair use rationale. Using one of the templates at Wikipedia:Fair use rationale guideline is an easy way to insure that your image is in compliance with Wikipedia policy, but remember that you must complete the template. Do not simply insert a blank template on an image page.

If there is other fair use media, consider checking that you have specified the fair use rationale on the other images used on this page. Note that any fair use images uploaded after 4 May, 2006, and lacking such an explanation will be deleted one week after they have been uploaded, as described on criteria for speedy deletion. If you have any questions please ask them at the Media copyright questions page. Thank you.

BetacommandBot 11:37, 6 July 2007 (UTC)

Children of Men

What does this movie have to do with Zero Population Growth? It's not a movie about a society with zero population growth, it's a movie about a society in which there is no more children. That's not ZPG.--RLent (talk) 17:39, 9 April 2008 (UTC)

Correct - zero growth is different from zero reproduction (which would result in rapid de-population). ·:· Will Beback ·:· 01:47, 10 April 2008 (UTC)

zero poulation growth

zero poulation is the taking of humans and making them only have 2 kids per couple —Preceding unsigned comment added by 67.172.242.254 (talk) 22:58, 23 September 2008 (UTC)

Thats not true at all, ZPG has a much worse agenda than that. The fact of the matter is that peoples lifespans have been increasing for quite some time, and will continue to do so. For this reason alone, 2 per couple results in population growth. —Preceding unsigned comment added by Zaphraud (talk • contribs) 03:24, 10 October 2008 (UTC)

Both of these comments are problematic. The birth rate to insure relacement is actually 2.1 children. Some people need to have more than two to make up for the fact that some couples have one or zero children, and some portion of that next generation will also not be fertile. The current replacement rate is actually currently (in 2009) much lower than the needed replacement rate in some parts of the world ---especially first world countries. This is worsened by the fact that women in first world countries are having their chilren later in life. Simplistic solutions such as limiting the number of children to two are not feasible to maintaining populations. There are concerns that culture will be lost as certain ethnic, religious, or other groups attempt to enforce the 2 children or less rule in their population. —Preceding unsigned comment added by unsigned (talk 08:24, 15 January 2009 (UTC) —Preceding unsigned comment added by 96.242.130.52 (talk)

Presumably the birth rate to ensure replacement is 2 children on average - where the average is calculated over all "couples" including those who have zero children (including those who are infertile). Mitch Ames (talk) 13:25, 6 July 2009 (UTC)

Negative population growth will most likely be required for many nations in order to avoid population collapses (starvation) because of exceeding biocapacity. List of countries_by ecological footprint 109.228.168.107 (talk) 23:37, 9 November 2012 (UTC)

I think this page needs to differentiate between global population growth and the population growth of a specific country. One of the ways to achieve ZPG on the current Wikipage is immigration. Moving people from one place to another has no impact on the global population. GreenCPA in Oregon (talk) 21:22, 18 December 2015 (UTC) GreenCPA in Oregon GreenCPA in Oregon (talk) 04:06, 13 December 2015 (UTC)GreenCPA in Oregon

"Effects," section edited 11 Dec 2015

Because by definition a population is at equilibrium when its overall birth and death rates are equal, I changed the explanation to note the time lag in demographic transition theory is between the time when fertility (not birth) first drops to replacement level and the time when population levels off. "Birth rate" and "fertility" are very different terms although easily confused. The birth rate is how many babies born each year per 1000 people. The fertility is lifetime children per woman, usually determined by asking women of various ages whether they've had a child that year and taking a weighted sum. The section title should probably be "Relation between changes in fertility and population growth" or something like that. I may make the title change later when I can source the explanation. Ehrlich is good, but I need a source that defines "demographic equilibrium" explicitly as meaning the same thing as ZPG, and gives step-by-step general process explanations which Ehrlich omits. I will try to add this source next to Ehrlich.

The replacement level fertility has a complex mathematical definition and is recalculated every year, constantly changing along with the other rates. This means the explanation as I've expanded it still has subtle defects. For instance, I said, "even though fertility has dropped to replacement level" while ignoring that the replacement level isn't really constant. But including this extra detail will make the explanation cumbersome and impair the reader's grasp of it.

A link to the general "Demographics" article would help; I'm not sure how to format it yet. Unfortunately, however, that article, although it gives the basic equations, doesn't offer detailed process descriptions for demographic transitions either. It needs a section on the age structure of a population (those pyramid things), and would involve differential equations and integration if it were comprehensive. Jessegalebaker (talk) 03:17, 11 December 2015 (UTC)

How did Antonin Scalia get into this article?

Is there a particular reason to bring Scalia into this? Did he rail against ZPG or something to make him the target of scrutiny?

(quote) "For example, Antonin Scalia had nine children and if each of those had nine and if in each generation each offspring had nine, then in just 11 generations about 31 billion Scalias would live on the planet. That is the power of compound growth." I like to saw logs! (talk) 15:28, 20 April 2016 (UTC)

Scalia removed

The sentence about Antonin Scalia is clearly a political statement in response to Scalia's death which Albert Bartlett, who died in 2013, could not have made, so I have removed it. Bartlett is cited as origin for every point in this section. The Bartlett material isn't free, but a U. of Colorado description, advert, and audio excerpt is at http://www.albartlett.org/presentations/arithmetic_population_energy.html

Unfortunately Bartlett was a physics professor, not a demographer or actuary. His off-the cuff exponential growth scenarios seem to have been cut out for the amusement of his students. Although he may have held pro-ZPG opinion; the material derives from a paper about energy use and the energy crisis he wrote in 1969 and converted into a speech he gave repeatedly thereafter. Here he discussed growth in fossil fuel consumption, not population itself, and omitted the mathematical treatment you need for a realistic model. This stuff isn't the best source for either demographics or ZPG, both difficult subject areas and not at all accessible to non-specialists. This Wikipedia article is fatally flawed in my opinion and needs rewriting from scratch by a qualified person, which simply isn't going to happen. More Bartlett on energy use, see http://www.albartlett.org/articles/art_forgotten_fundamentals_overview.html Jessegalebaker (talk) 12:28, 6 May 2016 (UTC)