It could be argued that no sooner had 15th century northern Italian markets expanded into western and northern Europe, than monarchs and lords also began to reshape governing institutions to take better advantage of these changes in production and knowledge, in which case private production and knowledge have always been intimately linked. Without institutions for revenue collecting, a means to raise and deploy armed forces, and population control (laws), private capital could not have made the advances in production and knowledge that it did beginning in the 15th century. But from that point forward, i.e., as early as the 15th century, it was private capital that was reshaping governing institutions in its image, and not the reverse.
Still, for whatever reason, the kinds of knowledge that were deemed valuable in the 15th century differ dramatically from the kinds of knowledge that R Lucas (and we?) currently have in mind. It was, after all, not too terribly long ago that institutions of higher learning valued the humanities and social sciences not merely as supplements to maximizing private capital’s return on investment, but as legitimate and essential fields of learning, research, and knowledge in their own right.
Since this is so, we might well wonder whether the increasingly private character of knowledge production and exchange, as well as the kinds of knowledge that are valued, reflects this shift over time from a still viable and reasonably independent public sphere; whose protection from private capital was deemed an essential part of protecting republican values and democratic institutions, to a public sphere whose composition, aims, ideals, and means are barely distinguishable from those of the private sphere; and whose forms of knowledge are produced in much the same way and valued for many of the same reasons as private capital.