微觀經濟學源自於古典經濟學與新古典主義經濟學，19世紀初嘅經濟學家大多追求研究所謂“財富嘅來源”，距地繼而延伸到分析個體嘅生產方法、生產物品係經濟體系中嘅分配和個體交換手段嘅經濟活動，生產、分配和交換就是早期微觀理論的三分法。微觀經濟學基本上是古典經濟學最主要嘅內容，宏觀經濟學當時並未被完全發展成完整的一套理論體系。當今在宏觀經濟學佔有重要地位嘅貨幣問題同國際貿易在古典經濟學被看作是微觀經濟學嘅一部分，19世紀晚期纔有學者爲此專門著書立説研究早期嘅貨幣理論，並把貨幣理論分離出微觀經濟學，係亞當斯密同李嘉圖及他們同代人嘅理論中，貨幣政策被概括為個體行爲中作討論，例如貨幣如何影響商品價值等。國際貿易在這時期的情況，也被視爲是延伸到國家層面形式嘅一種個體商品交換行爲。貨幣理論同國際貿易理論因爲涉及交換嘅特性而被列入微觀經濟學討論，但隨著三分法被放棄，這兩者也擺脫了原有框架，而轉爲按層面分類的宏觀經濟學。
Microeconomics originated from classical economics and neoclassical economics, and most economists in the early 19th century pursued the study of uranium, the source of so-called uranium wealth, and then extended to the analysis of individual production methods, economic activities in which the production of goods is the means of distribution and individual exchange in the economic system, and the trichotomy of production, distribution and exchange was implemented in the early micro-theory. Microeconomics was basically the main content of classical economics, and macroeconomics was not fully developed into a complete theoretical system at that time. In the late 19th century, a scholar wrote a book on the study of early monetary theory and separated monetary theory from microeconomics, which was discussed in the theories of Adam Smith and Ricardo and their contemporaries, in which monetary policy was summarized as individual behavior, such as how money affects the value of commodities. The situation of international trade during this period was also seen as an act of exchange of individual goods that extended to the national level. Monetary theory and international trade theory were included in the microeconomic discussion because they involved the nature of exchange, but with the abandonment of the rule of thirds, they also moved away from their original frameworks and into macroeconomics classified by levels.