The school Log Books from many Powys schools often give a good idea of the availability of local jobs at different times in the past. This entry from Ynscedwyn shows that the nearby collieries (coal mines) were doing well in 1888, but it also shows that some children were taken away from school because parents had to pay.
There are more examples of this on other pages.

This was written in November 1888:
"Several children have left school during this quarter [Term]. This is due to some extent to the School Fees Regulations, and partly also to the improved condition of the collieries in the neighbourhood which makes it easy for boys to obtain employment".

During the 64 years of Queen Victoria's reign the factories and mines were doing well in some years and very badly in other years.

There was a lot of competition from other areas and from new machinery and methods. Improved railway and other transport links also helped some areas more than others.

More about school and work...