Confusius, he say:
There was once a village, where several families lived, each with their own allocation of land, on which they grew their own food and kept a pig. After a few years, one family (The YUKs) found that if they had another pig, and intensified the food production on their plot of land, they got more food than they needed for themselves, and could sell the surplus to the other families. Another family (The YUSSES), seeing how the first family were doing so well, decided to do the same. Both families prospered, and bred more and more pigs. However, because they were now rearing more pigs, and creating more manure than the land could take, they decided to dump all the surplus in a swampy useless part of the village. A few years later, a third family (let's call them the CHINS) also decided to join the wealthy band of prosperous producers. Unfortunately, by this time the shit heap was overflowing with crap, and all the extra being dumped by the Chins just flowed out over the whole village, threatening the whole existence of the village as a sustainable entity. The YUKS and the YUSSES blamed the CHINS for the mess, but who was it who filled up the shitheap in the first place?