Investment is slow to increase.
The change of Britain from an agricultural to an industrial society was slower than previous authors had believed. As you read, watch how Crafts constructs his argument. Crafts's estimates, because they slow the growth rate, leave Britain in the eighteenth and seventeenth centuries considerably richer than previously thought. This should be seen as a point for Jan de Vries in his argument that the commercial economies of the seventeenth and eighteenth centuries were actually surprisingly modern. Landes is concerned with invention as opposed to economy-wide diffusion.