Interesting study of men's occupations in England and Wales between 1540 and 1799. The study is based on probate data, that is, records of estates, which almost always list the profession of the deceased. The data shows that the share of men working in agriculture fell a great deal across this period. For the 1700s this is not at all surprising or controversial, since the industrial revolution and the accompanying urbanization of England and lowland Scotland were already well under way. The interesting discovery is that the share of men in agriculture had already fallen quite a bit by 1700. For England as a whole, the share of men in agriculture fell from about 65% in 1600-1620 to 50% in 1700-1720. That number elides major local differences; in some counties there was little change but it others it was quite dramatic. The suggestion is that the English economy was already diversifying and becoming less agricultural well before the first spinning jenny was installed in a mill. This is what I would expect, given the explosion of world trade, shipbuilding, and so on, but it has been very hard to document.
There are a lot of problems with this approach, the main one being that less than half the men in Britain were noticed by the probate courts. Richer people were more likely to be noted, but some rich people don't show up and some who owned nothing do, and nobody really knows why. Since we don't know what logic was used, as far as we know it might have changed over time. The authors of this study don't actually assert that their numbers represent the real number of men working in or out of agriculture, but they assume that the method remained more of less the same, so the comparison has value even if the numbers are wrong.
One reason to have some confidence in the numbers is that they show no change at all in 17th-century Wales, which matches what everybody at the time said about Wales being a rural backwater. It seems that the Welsh economy did not begin to modernize until the rise of coal and steel in the 18th century.