One of the things that I wish that I had paid more attention to when I was at work is the interaction between economics and demography, and it has been a recurring them in this discussion.
The other thing that strikes me in this discussion is trying to separate the economic and demographic changes that are affecting lots of businesses from those that have a specific impact on railway preservation.
Starting with demography, here is an interesting article on the ONS website. It is more than 10 years old now, and the coverage is England and Wales, but it does show most of the relevant information, including some pictures that are worth a thousand words.
Across the twentieth century the number of live births have fluctuated, with sharp peaks at the end of World Wars 1 and 2. Live births peaked at near post-war levels again in 1964 (875,972 births), but since then lower numbers have been seen. The lowest recorded annual number of births in the twentieth century was 569,259 in 1977.
The sharp peak in births at the end of World War 2 is particularly significant, and I call it the 1946 effect. There was a big spike in births in 1946: those babies were 12 at the start of implementation of the Modernisation Plan and 22 when steam ended on BR. They are now 79.
The peak in the birth rate in 1964 is also significant. Those babies were 12 when the Westerns were withdrawn in 1976, and 24 in 1988, when the sprinter invasion was at its peak. This age group are now getting near to retiring or retired already. They are the UK baby boomers, and not to be confused with the USA baby boom which happened much more quickly after the end of World War 2.
The number of births to women born outside the UK has risen every year since 1995, with a marked rise since the turn of the century. Previous analysis using 2013 data shows that the European Union (EU), excluding the UK, represented 8.7% of all live births. Births to mothers born in one of the 13 countries that have joined the EU since April 2004 represented the majority of these births (6.1% of all live births). Mothers born in the Middle East and Asia contributed 9.5% of all live births while mothers born in Africa contributed 5.2%
I would be wary of reading too much into this, and I'm going to stray into anecdote to explain why. I have 3 nephews, only one has had children so far, but all of 3 of them have partners born in the EU excluding the UK. For railway enthusiasm, the National origin of the father is likely to matter a lot more than the National origin of the mother.
Moving onto economics, much of what is being discussed here are changes in costs that affect lots of businesses. In the particular cases of the minimum wage and Employers' National Insurance, volunteering insulates preserved railways from the full effect of these felt by other businesses. On the other hand the price of coal does affect steam railways more than most businesses.
But the general economic situation does matter too, because it affects demand. Large numbers of people have their economic decisions constrained by the "cost of living" crisis, and this impacts hard on families with children.
In a different part of the economy, the economic behaviour of seniors has changed as a result of covid. A good example of this affecting the wider economy was recently in the buses section of this forum: the sector of bus travel that is still furthest away from recovering to pre-covid levels is ENCTS, seniors bus passes. And that's despite the travel being free to the user.
This matters for preserved railways because one group of preserved railway customers often ignored by enthusiasts is the coach party, with a clientele dominated by seniors. In this part of the world Richmonds of Barley are a big player, running about 200 day trips per year. I have checked the 2025 list and it only has 6 preserved railway trips, 4 to the North Norfolk at £46 and 2 to the Bure Valley at £49. I don't know how this compares with before covid, but it doesn't strike me as a big number of trips.
Broadly speaking my conclusion is that the economic impacts are not specific to preserved railways, but there are some predictable demographic trends that hit preserved railways in some quite specific ways, because of the way that demography has correlated with significant events in railway history.