Bibliographic record
Abstract
The second half of the 20th century saw the more developed countries of the world experience population ageing to a degree hitherto unseen in demographic history.The first half of the 21 st Century is predicted to see the same transition within the less developed and transitional countries.Globally, by 2050 there will be some 2 billion adults aged over 60, and the total number of older people will outnumber the young.This is historically unprecedented.It makes the 20 th century the last century of youth, the 21 st century the first of population maturity.Most western style countries have aged continuously over the past century, the measure of ageing being an increase in the percentage of those over 60 years, and a decrease in those under 15 years.Europe reached maturity at the turn of the millennium, with more older people than younger.By 2030 half the population of Western Europe will be over 50, 25% over 65, and 15% over 75.By 2030 one quarter of the population of the developed world will be over 65, and by the middle of the century this will have risen to one third.Yet while most interest has focused on the ageing of Europe, it is the Asian/Pacific region that is ageing most rapidly.By 2030 one quarter of the population of Asia will be over 60, and by 2040 Asia will be demographically mature, with more older than younger people.If we move from structural ageing to consider absolute numbers of older people, the dominance of the less developed regions, and in particular Asia, becomes even more apparent.Already two thirds of the world's older population live in less developed regions with the absolute numbers of older people in these regions doubling to reach some 900 million within 25 years.By 2050 two-thirds of the world's elders will live in Asia alone.The numbers of those aged 80 and above will show an even greater increase, rising from 69 million to near 400 million by 2050.Thus by the middle of the 21st Century there will be almost as many over 80s as there were over 65s at the beginning.This is the fastest growing age group in the world with an annual growth rate of 3.8%.Low fertility around the time of the First World War and declining
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.009 | 0.046 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.005 | 0.004 |
| Science and technology studies | 0.003 | 0.005 |
| Scholarly communication | 0.013 | 0.009 |
| Open science | 0.002 | 0.007 |
| Research integrity | 0.008 | 0.012 |
| Insufficient payload (model declined to judge) | 0.074 | 0.035 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".