From Gemini:

While David Ricardo is the name most famously associated with the discovery of comparative advantage, the history is actually a bit of a "confused tangle" involving three key figures:

1. David Ricardo (1817): He is credited with the definitive formalization and popularization of the theory in his book On the Principles of Political Economy and Taxation. He used the famous example of England (cloth) and Portugal (wine) to show that trade is beneficial even if one country is more efficient at producing everything.
2. Robert Torrens (1815): He actually published a very similar idea two years before Ricardo in his Essay on the External Corn Trade. Some historians argue he is the "true" father of the concept, though Ricardo’s version was more mathematically rigorous and influential.
3. James Mill: Ricardo's mentor and the father of John Stuart Mill. Some scholars believe Mill actually came up with the core logic and prodded Ricardo to include it in his book to strengthen the argument against the protectionist Corn Laws.

In short: Torrens likely published it first, Ricardo made it famous and proved it mathematically, and James Mill may have been the "ghostwriter" or intellectual catalyst behind it.

The concept was first described in print in 1815, but the actual term "comparative advantage" did not appear until later.

• The Idea (1815): The logic was first published by Robert Torrens in his work An Essay on the External Corn Trade. While he explained the principle—showing that a country could benefit from trade even if it was less efficient at producing everything—he did not use the specific phrase "comparative advantage."
• The Famous Formulation (1817): David Ricardo published the most famous explanation of the theory in his 1817 book, On the Principles of Political Economy and Taxation. Interestingly, even Ricardo only used the term "comparative advantage" once in the entire book, and some scholars argue he wasn't using it in the modern technical sense there.
• The Term (1821/1826): The specific term "comparative advantage" began to be used more formally in the 1820s. James Mill used it in his Elements of Political Economy (1821), and Robert Torrens used it "correctly" in the modern sense in the 3rd edition of his essay in 1826.

Summary Timeline:

• 1815: First appearance of the concept (Torrens).
• 1817: Most famous formalization of the concept (Ricardo).
• 1821–1826: First regular use of the actual term in print.