2026 The start of Population deline?

I grew up worried that the world's population would grow too much and widespread hunger would result.
But I think 2026 is the year there will be a move to a long term drop in the world's population. 
By this I mean that

1. World fertility will continue to decline at the same rate as it has been recently. So TFR of 2.3 in 2023 going to 2.25 2024, 2.20 2025, 2.15 in 2026.

2. Infant and child mortality will decline at the same rate as it has been recently. It is down to about 3.5% from 9.7% in 1990. Malaria, TB and other vaccines might reduce this considerably but fairly slowly and not much by 2026.

3. Sex selective abortion will continue to decline but not fast enough to keep females being born above replacement level.

Long term it is number of women that are raised per woman that matters. If our life expectancy goes from 40 to 80 to 120 that's really good for us. And it will mean the world's population goes up. But not in the long term.

Long terms it is really women that matter. They are the ones that actually have children. Obviously this men not mattering idea is not true at the extreme end. You do need some men.

Assuming life expectancy and men do not matter. What does matter in particular is number of female children per woman. And particularly how many of those live to an age when they can have children.

And I think these align so that we move below replacement level in 2026. 

The year of peak births seems to have been 2013 and to have moved to below long term replacement that soon afterward is quite surprising. Getting the exact year is hard as in some ways we won't know how many people get to the age they can have children until they get there. At a 1% yearly decline in fertility we will be below replacement birth level soon.

Ireland Population Density Maps

Data from https://ec.europa.eu/eurostat/web/gisco/geodata/reference-data/population-distribution-demography/geostat which has population grid at a 1km² population sizings for all of Europe in 2011. The code is very slightly modified version of the code developed by halhen and p0bs here https://gist.github.com/halhen/659780120accd82e043986c8b57deae0

Color Maps

Joyplots

Where population density is seen as an increase in height.

Other Countries

Irish Alcohol Consumption in 2020

Drink blitz sees bottle of wine rise to €9 minimum 'Irish people still drink an annual 11.6 litres of pure alcohol per capita, 20pc lower than at the turn of the last decade. The aim is to bring down Ireland's consumption of alcohol to the OECD average of 9.1 litres in five years' time.'

What would Irish alcohol consumption be if current trends continue? Knowing this the effectiveness of new measures can be estimated.

The OECD figures are here. I put them in a .csv here.The WHO figures for alcohol consumption are here I loaded the data in R Package

datavar <- read.csv("OECDAlco.csv")

attach(datavar)

plot(Date,Value,

     main="Ireland Alcohol Consumption")

Which looks like this

Looking at that graph alcohol consumption rose from the first year we have data for 1960 until about 2000 and then started dropping. So if the trend since 2000 continued what would alcohol consumption be in 2020?

'Irish people still drink an annual 11.6 litres' I would like to see the source for this figure. We drank 11.6 litres in 2012 according to the OECD. I cannot find OECD figures for 2014. In 2004 we drank 13.6L the claimed 20pc reduction of this is 10.9L, not 11.6L. Whereas the 14.3L we drank in 2002 with a 20pc reduction would now be 11.4. This means it really looks to me like the Independent were measuring alcohol usage up to 2012.

Taking the data since 2000 until 2012.

newdata <- datavar[ which(datavar$Date > 1999), ]

detach(datavar)

attach(newdata)

plot(Date,Value,

     main="Ireland Alcohol Consumption")

cor(Date,Value)

The correlation between year and alcohol consumption since 2000 is [1] -0.9274126. It look like there is a close relationship between the year and the amount of alcohol consumed in that time. Picking 2000, near the peak of alcohol consumption, as the starting date for analysis is arguable. But 2002 was the start of this visible trend in reduced alcohol consumption.

Now I ran a linear regression to predict based on this data alcohol consumption in 2015 and 2020.

> linearModelVar <- lm(Value ~ Date, newdata)
> linearModelVar$coefficients[[2]]*2015+linearModelVar$coefficients[[1]]
[1] 10.42143
> linearModelVar$coefficients[[2]]*2020+linearModelVar$coefficients[[1]]
[1] 9.023077
> 

This means based on data from 2000-2012 we would expect people to drink 10.4 litres this year. Reducing to drinking 9 litres in 2020. So with current trends Irish alcohol consumption will be lower than 'the aim is to bring down Ireland's consumption of alcohol to the OECD average of 9.1 litres in five years'.

There could be something else that is going to alter the trend. One obvious one would be a glut of young adults. People in their 20 drink more than older people. If there are a higher proportion of youths about then the alcohol consumption will rise all else being equal. So will there be a higher proportion of people in their 20s in 5 years time?

The population pyramids projections for Ireland are here. Looking at these there seems to have been a higher proportion of young adults in 2010 than there will be in 2020 which would imply lower alcohol consumption

it would be interesting to see the data and the model that the prediction of Irish alcohol consumption are based on. And to see how minimum alcohol pricing changes the results of these models. But without seeing those models it looks like the Government strategy is promising current trends to continue in response to a new law.

Predictions for 2030

I have no idea what will happen to the euro in the next month. And whatever happens will have big consequences. Yet I was willing to make predictions for 2030 about lbr, driverless cars, solar power and education in my last post.

The thing is I think I am cheating with technology predictions. Theres a wildly unpopular branch of Marxism that argues for technological determinism. Marx can be interpreted as saying that our technology is inevitable and will change us in unavoidable ways. "The windmill gives you society with the feudal lord: the steam-mill, society with the industrial capitalist"

After reading "What technology wants" by Kevin Kelly I am a convinced technological determinist. There is a podcast from Kelly on technology at econtalk

The book makes a compelling case that

1. You cannot shut yourself off form technological change. The Japanese tried it and failed. The Amish dont try it, they stay about 50 years behind on average but they do not avoid new technology forever.

2. No technology ever dies out.

3. Each new technology is an inevitable consequence of the last. No one person of country can cause or prevent a new technology, though they can shape its exact form.

Almost all patents of significant technologies have multiple very similar independant patents lodged at nearly the same time. Airplanes, radio, transisters, computers, television whatever you can think of about three guys thought of it and implemented it independantly within a few months of each other. This suggests that once the right prior technologies exist the next one is inevitable.

Kevin Kelly: What Technology Wants

Keynes wrote about 2030 in 1930 in the article “The Economic Possibilities for Our Grandchildren.” which has been surprisingly on accurate for the last eight decades. So I am betting it will continue to be for the next two. He made brought claims about future growth rates that have been accurate. I will make similar claims now. Given that I dont think non technological predictions can be made I am going to try anyway
1. Grinding poverty will be gone. This is a low bar of 365 dollars a year in 1990 dollars. Thats really bad. Much worse than medieval England but it is one I think we can reach.

2. Polio and guinea worm will be eradicated.

3. World population will be slightly lower than the medium UN estimate of 8321380. The high is 8776486 and the low is 7867332. So I will guess 8250000.

This is just a few predictions based on the world continuing to go the way it has for the last two hundred years. But like I said I cannot predict what will happen to the cash in my pocket over the next two months so two decades away is being ambitious. If you have any predictions for 2030 please put them in the comments. It might be fun for the floating brains in a jar to laugh at them at the time.

The Population Surge is Stopping

Population surge difficult to halt and almost impossible to reverse was published yesterday in the Irish times. It is also availible in blog form here. The article makes some interesting and arguable claims about human environmental damage to the planet. These are based however on claims about human population that do not match the evidence or the UN's demographic predictions.

Today, just like every day for the last 50 years, around half a million babies will be born.

This is not true the figures from the UN are here. In detailed indicators look in births and in select country look in world.
Between 1960-1965 302136 babies were born each day. Between 1985 and 1990 375909 babies and between 2005 and 2001 367320 babies. The 500000 figure is not just wrong but drastically wrong.

The geometric nature of population growth makes it extraordinarily difficult to arrest, and almost impossible to reverse. The last population doubling took only 40 years. Even if global population growth rate drops to just one per cent, today’s seven billion would swell to an unimaginable 14 billion in 70 years.

The growth rate is being arrested. As I have said before in "We have reached Peak Baby" the number of children each woman has has been falling for decades.

"1968 women got 1.87 adult daughters. Ehrlich called it population bomb. Now women get 1.07 daughters, 92% of way to population balance done." Says Hans Rosling. In 43 years we have gone from 1.87 adult daughters to 1.07 a decline of .8 and we only need a decline of .07 more to reach long term balance of the numbers of women. Rural agrarian Bangladesh has reached stasis in adult female population levels for example.Look at the gapminder video here for yourself the number of children per women is declining

Though surprisingly accurate population estimates get better over time. For example the 2050 estimate has been recently honed in

U.N. Raises “Low” Population Projection for 2050
The "low-variant" scenario of population growth now foresees 117 million more people on the planet in 2050 than it did two years ago.
While the "median-variant" scenario, often seen as "most likely," remains almost the same as before - predicting a world with 9.2 billion people by mid-century
...
The high projection, however, foresees some 10.5 billion people - a 295 million person decrease from the previous high projection. The medium projection is 9.2 billion people,

It says something that an decline in the high estimate an over 2.5 times bigger than the increase in the low estimate is not the headline.

There are still countries that have very high birth rates per woman. Senegal for example had 7.5 babies per woman in 1968 4.8 babies and in 2010. But these countries are developing at a speed that is likely to see these birthrates drop rapidly. "Senegal has lower borrowing costs than Ireland." and a GDP growth rate of 4.2%. As these countries that still have a high birthrate develop their birthrate will drop rapidly the way ours and other developed countries did.

The article is in the Irish Times gives the wrong figure for the number of births per day and "unimaginable 14 billion" scare figure. The demographic evidence and historical trends indicate the population will not go to this level. Current UN estimates are for the high population prediction do not match this figure for 2081. There were never that many babies born per day and the birthrate has been falling so fast that we will not reach the 14 billion in 2081 figure.