Martin Kolk
@MartinKolk
Followers
2K
Following
1K
Media
336
Statuses
2K
Demographer at Stockholm University @SUDA_Sthlm, and the Institute for Futures Studies @Framtidsstudier
Stockholm
Joined May 2017
In a new study in Population Studies, I show that income is associated with higher childbearing in Sweden. The differences are large and are found for both men and women. I accumulate annual income histories from age 20-60 to estimate life course income. https://t.co/e5WInAJkQ8
tandfonline.com
This study uses income accumulated over ages 20–60 to examine whether richer or poorer individuals have more children. Income histories are calculated using yearly administrative register data from...
10
44
224
The absolute number of births in Taiwan will soon decline even more in the next 10-15 years. This will happen when women born 2000 to 2010 (~ age 25 to 15) replace those born in 1985 to 2000 (~ age 40 to 25). This will also happen with modest fertility recuperation.
Taiwan's demographic reality check: Birth rates have plummeted to just 8,603 newborns in September 2025, representing a staggering 27% decline from the previous year. ★ https://t.co/8mPruf2JJF ★
2
5
18
Här kan man se en diskussion med mig och andra om barnafödande i SVTs kulturnyheter, där det vrids och vänds på sjunkande barnafödande i olika perspektiv. https://t.co/PwdcPTKxIT
svtplay.se
Sverige har idag de lägsta födelsetalen sedan 1751 och regeringen har tillsatt en utredning för att svara på varför. Men även runt om i världen sjunker födelsetalen. Handlar det om politik, teknik,...
0
1
6
If you ever wanted a case example on how to not to mix up statistical uncertainty, with scenario uncertainty or forecasting intervals for forecasting, I think you will struggle to find a better case than this one.
1
1
2
It also illustrates that if the 1990s cohorts of South Korean women do not soon catch up, and have children in their late 30s, long-term population will accelerate. The extent current low ASFR of women in South Korea is/is not postponment is critical for Koreas long-term trends.
0
0
4
Excellent illustration of how age structure affects population growth. Compare the 2010 and 2025 age pyramids for South Korea, and you can easily see why you in 2010 still have some years of growth left, also with low fertility, and why population decline is inevitable in 2025.
Despite its dismal fertility, South Korea's population is actually increasing. Manchuria however looks bleak
3
14
69
In Sweden, a substantial majority say that people should factor climate concerns into reproductive choices. Almost a quarter believe that Sweden should introduce measures to reduce fertility in Sweden out of climate concerns (despite Sweden having sub-replacement fertility).
In our new study in Population & Environment, we examine how environmental concerns shape public attitudes toward childbearing in Sweden. We find views linking environmental concerns with reproduction are widespread, even if we find less support that they affect behavior.
17
32
297
Read the paper by Kirsti Jylhä, myself, and Malcolm Fairbrother for many more details, more models, and more thoughts on the complex relationships between people's views on population, reproduction, and how they are related.
1
0
1
However, the widespread agreement to link childbearing with environmental concerns could influence societal norms, and future policy debates on reproduction and sustainability.
1
0
2
We conclude that while environmental concerns are shaping how people think about population and childbearing, these attitudes haven't yet affected fertility.
1
1
4
People with climate worries and propensity for climate action are more worried about the future of a child living in a deteriorating world, than that an additional child may contribute negatively towards such a future. We find weak correlations with political attitudes and trust.
1
0
2
Different eco-reproductive concerns are moderately correlated with each other, and weakly correlated with whether people have children or not. We find that the same people largely support policies reducing population both in their own country, and in developing countries.
1
1
4
People generally agreed both factors are important.While 65-70% of respondents said in principle that environmental problems should factor into childbearing decisions.
1
0
2
In a second study, with over 600 participants, we asked how much environmental factors should influence childbearing - both the impact of a worsening environment on the child, and that an additional child may contribute to an increasing population that may worsen the environment.
1
0
3
We find that younger people and women are more worried about climate change, while men are more concerned about overpopulation. Parents with more children tend to be more concerned about future generations but less worried about overpopulation.
1
0
3
Our first data set is 8,000 respondents in the Swedish Gender and Generation Survey. Respondents were asked about worries such as climate change, overpopulation, and the prospects of future generations. Worries about three things are widespread.
1
0
2
The study focuses on eco-reproductive concerns—the idea that environmental challenges should influence personal and societal views on childbearing.
1
0
2
We do not find that individual decisions about having children are clearly shaped by environmental concerns, but many people believe such concerns should play a role in reproductive choices.
1
0
6
In our new study in Population & Environment, we examine how environmental concerns shape public attitudes toward childbearing in Sweden. We find views linking environmental concerns with reproduction are widespread, even if we find less support that they affect behavior.
7
5
42