I can give you answers specific to eighteenth-century Britain, which you may find informative since Britain is typically cited as the vanguard of Europe's Industrial Revolution. First, I'll provide a summary of what 18th century Britons thought about your question, and then a summary of what modern historians think about 18th century Britain's industrial revolution.

A popular answer to that question during the 18thc. rested on what is referred to as "stadial theory." It proposed that a society's mode of subsistence correlated to the amount of leisure time individuals had, which could be devoted to technological invention. During the 18th century, these modes were typically divided, progressively, into 1) hunter-gatherer 2) pastoral 3) agricultural and 4) commercial. The "further" a society had advanced through these modes, the more surplus time and resources they had to devote to technological invention. The biggest advocate of this theory, according to historian Ronald Meek, was none other than Adam Smith. And indeed, a genealogy of this kind of thinking can be traced from Smith to Karl Marx's nineteenth-century economic theories, where "modes of subsistence" have been transformed into "modes of production." (See: Ronald L. Meek's book, Social Science and the Ignoble Savage).

Of course, this idea only represents what contemporary Britons imagined were the cultural characteristics that engendered technological invention. Modern economic historians, Joel Mokyr is perhaps the most notable, have advanced a thesis specific to 18th century Europe (Britain especially) and the so-called Industrial Revolution. Mokyr argues that the key causes of Britain's technological booms in textile manufacturing, coal mining, and metallurgy were reforms to British patent law. Although the English patent--which guaranteed a fourteen year monopoly on inventions--had existed since the passage of the Statute of Monopolies in the early seventeenth century, in practice it rarely functioned as we think of patents today. During the late 1710s, reforms to the Statute of Monopolies (collectively known as the "Statutes of Anne") effectively united the experimentalism of the seventeenth-century with the nascent free market principles of the eighteenth. They did so by guaranteeing inventors the same fourteen year monopoly on their invention, but also required the publication of said invention's working and design. This exchange of short-term private gain for a long term increase in what Mokyr calls "useful knowledge" resulted, he argues, in the technological boom of Britain in the second half of the eighteenth century. (Mokyr has several books and articles on the subject such as "The Lever of Riches" and "The Enlightenment Economy.")

Hope that helps.