I think the technology of artificial selection is/ will be the most important determinant for accelerating ever expanding economic growth. Do you agree?
Technological evolution is definitely a continuation of biological evolution; concerning selection pressure and procedures, I do think that economic growth depends fully on human ingenuity and creativity (https://en.wikipedia.org/wiki/Spontaneous_order).
I am certain that Stephen was not trying to be exclusive in his answer in focusing on some important elements of economic growth (i.e., human ingenuity and creativity). Available resources, technology, trade, and other factors such as the extent to which an economy is advanced compared with hunting and gathering societies, for example, are likely to be significant in economic growth as well.
Interdependence and synergy between and among various factors likely exists and plays a role. History suggests all economic growth did not always use the exact same recipe.
Addressing the original question more directly seemingly needs a definition of artificial selection as Emmanuel implied. However, unless the meaning of artificial selection somehow includes all human behavior (i.e., it is somehow all-inclusive), it would be challenging to identify which of these is categorically the most important for all economies in all circumstances.