李嘉图经济学

邊際效應遞減

另一個讓李嘉圖出名的概念出自他的關於玉米低價格對於股票收益影響的隨筆，這就是著名的邊際效應遞減法則 (李嘉圖, 經濟學隨筆, Henderson 826).所謂的邊際效應遞減法則說的是如果對一個生產要素提供更多的數量而對另外一個生產要素保持數量不變，則總產量created by the extra units will eventually get smaller to a point where overall output will begin to fall ("Diminishing Returns").
舉一個例子，考慮一個只有兩資源--勞力和土地的簡單農場。假設該農場有一百畝土地及一名工人(勞力資源)。這個地-工組合可達到一定程度的產出。 如果我們增加土地且勞動力不變，該工人對每畝地的照料程度就會下降(假設其他條件皆不變)。所以，產出可能會增加，但單位土地的產量可能下降。如果我們繼續增加該名工人須照料的土地，最終會因土地過剩而導致工人分身乏術，總產量開始下滑(及分配給各畝田的勞動時數減少) 。這就是典型的邊際效應。 This is the typical stylized result of increasing one productive input while holding the others constant (versus increasing all inputs, generating economies of scale).

李嘉圖經濟學今日的應用

儘管大衛 李嘉圖是19世紀人物， 很多人在日常經濟學中還在引用他的工作成果. 李嘉圖的rent理論主要包括農民和地主的農業模式。由於高生產力的土地能夠生產更多的農作物，市場將支付相同價額購買有利和不利的土地上種植的作物，農民願意付出更多錢來買高生產力的土地來種植更多的作物掙錢（Henderson 827).
李嘉圖也有另一個有影響力的理論：最低工資。他知道如果較大幅度的人口增長，就業需求就會增加，使得工資下降到一個水平上，因為很多人願意採取低工資的工作，從而得以生存（聖克萊爾9，Fusfeld 325）。這個觀察最低工資的工作成果，尤其是今天顯得極為正確，只要看一看與執行最低工資法相關的爭議便明白了。。在他的著作政治經濟學和稅收原理中,李嘉圖說，工作提供更多的工資給我們珍惜的工作，而不是那些不珍惜的。對李嘉圖而言,價值和生產成本有很大關係，後者包括工資和利潤 (St. Clair 27) 並且，你支付多少錢給工人影響產品的價格。他還認為the value of a product was related to the quality of labor necessary for the production (Principles of Political 5). An example of this would be paying a slightly higher price for an item that is handmade, rather than being manufactured. Though this is true, 李嘉圖 also thought the labor or machine itself should be considered when selling an item and that a little of every item should be priced to include this factor of labor (St. Claire 24). 李嘉圖解決我們今天的經濟世界所面臨的許多問題，如最低工資和租金(Fusfeld 325).也許這些問題對我們非常重要，正如他們在19世紀的時候一樣，這是為什麼大衛李嘉圖的經濟學理論是現代經濟學的重要組成部分。

引文

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