For the purposes of this debate, “supply-side” arts funding consists of the government funding artists, institutions, or cultural projects directly. Eg. The Arts Council in England provides grants to museums, theatres, artists etc.
“Demand-side” arts funding consists of directly providing individual citizens with vouchers to spend on cultural products of their choice. Eg. The "Vale cultura" in Brazil allows citizens to spend on books, concerts, courses, cinemas etc.