For instance, agriculture has never been subject to any form of registration. Judged in the light of modern-day standards, many agricultural activities are characteristic of an underground economy. Hog raisers can operate wherever they want and raise as many hogs as they like, so they all run to the sources of streams to "set up a factory."
譬如過去農業完全沒有登記制度，以現代的眼光來看，許多農業活動都是地下經濟，養豬高興在那裡養、要養多少都可以，也因此養豬戶為方便清理豬糞，全都跑到河川源頭去「設廠」。