威廉·配弟在1662年就提出土地为财富之母,劳动则为财富之父和能动因素,李嘉图则指出,价值理论中土地是关键。
In 1662 , William Petty said that " Land is mother of wealth ; labor is father of wealth and passive factor " . David Ricardo pointed out that land was the key to value theory .