EconLog

pre-20th: Walras, for introducing the importance of marginal analysis

20th century: Milton Friedman, for elucidating the moral necessity of free markets

The most influential 20th century economist is probably Lord Keynes.

For pre-20th-century: Thomas Jefferson. Strong champion of small government, but not such a pendant that he'd pass up a deal like the Louisiana Purchase...

20th century: None qualified.

Seems like a dumb question to begin with. Historically, there is most definitely a "long tail" of influential people. A better question would have been "pick an influential person and explain what they influenced, the scope of their influence, and how they did it."

To that question, I would answer Copernicus. Dude singlehandedly sparked the Enlightenment by showing that the dominant intellectual power of the time was full o' beans.

No comment on pre-20th, but for the 20th century I would say Friedrich Hayek. Having such a heavy influence on Reagan and Thatcher is no small feat.

That's a tough question and more grounded in opinion than anything else.

I could see reasonable arguments for a lot of people pre-20th century. Y'got your Jesus, your Aristotle, your Isaac Newton, etc etc.

And 20th century is large in number too. However, I should like to put forth a name that has probablly touched most of humanity and will doubtless continue to be relevant until we evolve into beings of pure reason that lack physical bodies: Alan Turing (I know, I know, lots of people were involved with computers, but they call it Turing-Complete for a reason).

Malthus must be counted the most influential pre-20th century economist -- among other things Malthus helped inspire the Darwinian revolution in biology, which changed everything.

The most influential economists of the 20th century?

For the good -- Friedrich Hayek.

For the bad -- John Maynard Keynes.

Hayek transformed economics -- and public policy around the world -- by putting price signals and the division of knowledge at the center of social thinking.

Keynes helped wreck modern economic thought with the creation of an economics incompatible with all that economists had previously known about scarcity, savings, capital goods, money, and economic coordination through time in an open economy. Mathematical "model building" came to replace economic thinking among professional economists, leading to the current and continuing age of deficits and inflation for as long as the eye can see.

This is not an easy question. Your comment about Marx is certainly on the mark - he was not a positive force. Groucho was but I suspect you mean Karl.

But on the serious side I would offer Hayek first. Hayek comes back to me frequently on a daily basis. He did some of the best work on economic knowledge and how individuals function in markets. He blew Keynes away consistently. He thought carefully about the risks of making economics a numbers based profession. and he pointed out the moral hazards of socialism and bureaucracies.

But Smith would certainly be a close equal or second. My problem is that most people quote him without reading him. They do not understand his truly moral notions. He was a profound thinker.

In a clear place of second is James Buchanan. That might be limited to this century but he would be up there. Buchanan and Tullock changed the way we think about bureaucracies and political behavior. They spawned a group of economists who for the most part continue to help our understanding of human behavior in these areas. But as I think about it Hayek keeps coming back for his contributions across such a wide range of areas.

Reagan read Hayek?

Keynes created deficits?

"Walras, for introducing the importance of marginal analysis"

Yes and he demonstrated the existence of a general equilibrium, which should have lead everybody to realise that Marx did not know what he was talking about. But he lived and died in obscurity, and his best known student Pareto did not champion his work. He was right, but not influential.

Copernicus died 1543. the enlightenment dates, at the earliest, from the end of the 17th century. P.S. Copernicus did create a heliocentric system of astronomy. But, it was still an exercise in mathematics and geometry. It was Kepler who created a mathematical system that allowed astronomy to become a physical science.

Yes, it's well established that Reagan read Hayek. Reagan also refers to Hayek in various of his speeches. And during his Presidency Reagan invited Hayek to the White House. Many on Reagan's staff where also influenced by Hayek. For details, see for example Martin Anderson's _Revolution_.

Yes, it's well established that Reagan read Hayek. Reagan also refers to Hayek in various of his speeches. And during his Presidency Reagan invited Hayek to the White House. Many on Reagan's staff where also influenced by Hayek. For details, see for example Martin Anderson's _Revolution_.

Can I vote for JS Mill as an economist? I definitely think Keynes for 20th Century, by a long shot.

If you are gonna hang Marx for how Russia turned out then you have to give him credit for China.

I'm sure the spectacle of America surviving on charity from a Communist country has Marx smirking in his grave...

Your justification for the most important person in world history is John Locke because he was a major influence on American revolution and constitution! How provincial! I agree that the American revolution and constitution are major historical events, but so were the French, Russian, Chinese, English revolutions, the European empires, etc.

In terms of the biggest influence on world history I would tend to go for Aristotle and his development of enquiry about the natural world (or maybe Francis Bacon for his formalisation of the scientific method. The development of science is of far more importance to the modern world than any number of political revolutions and constitutions.

As for influential economists:
- pre 20th century - Adam Smith because he got it all started and had the "invisible hand" insight.
- 20th century - Lord Keynes. Gave an intellectual justification to governments doing what they loved.
However while I think Lord Keynes was the most influential economist in the 20th century, I do not think he will prove to be the most influential of the 20th century economists in the long-run. I'm inclined to pick out Hayek, Becker, Lucas for that second title.

Alfred Marshall is almost pre 20th century, right?

I think it might be easier to do a "10 Most Influential All-Time" list: Smith, Mill, Keynes, Samuelson, Ricardo, Marshall, Hayek, Walras, Marx, Velben is my list, though I'm sure I've forgotten someone.

I'd also note that these lists tend to have a Western bias, and I mean this in a real and not in a "let's be PC" sense. For instance, a list of mathematicians or scientists would surely include a handful of non-Westerners, and a list of "top explorers" would be something like Zhang Qian, Lewis/Clark, Gagarin, Magellan, Cook, de Gama, Zheng He, Marco Polo, Ibn Battuta, Columbus, with apologies to Drake, Erikson, Dezhnev, Mackenzie, Amundsen and Balboa. That's a top 10 with 4 from outside W. Europe. Surely there's been an influential economist from outside the Western schools?

Pre - 20th most influential: Adam Smith. For singlehandedly initiating the distinct discipline of economics.

20th century most influential : John Maynard Keynes, for better or for worse.

Outside the West? Dude, I'm Filipino, and from where I stand that's like asking which non-Western was most influential in the history of physics. Interesting, but empty.

Ronald Reagan was possibly the most influential. He had a degree in economics, his portrait is on the Chicago Boys blog. He also won the cold war against the Russians, with great economy of lifes and resources. A great economist if there was ever one.

Unless i'm mistaken you've asked for the most influential 'economists', however i'm seeing replies with Jesus and Newton in them!! Correct me if i'm wrong but they're anything else but economists!

Louis Bachelier, right in 1900. Although he probably never intended to contribute anything to economics.

I think the most influential 20th Century economist would be Paul Samuelson for a very obvious reason: he wrote the standard economics text that most people read for 50 years. I'm sure a lot of people around the world first encountered economics via Samuelson's text and that has had an impact.

Pre-20th century: I vote for Jean-Baptiste Say. His immense influence has yet to be recognized, because it matches that of Adam Smith and surpasses Ricardo in modernity.

20th Century: I can't name one, but give a semi-chronological list. Marshall, Keynes, Samuelson, Friedman, Lucas, Hayek... All of them have had enormous influence.

As Chou En-lai said about the influence of the French Revolution, "It's too early to tell."

But:
20th century: Keynes took the early lead but I think in time Hayek and Coase will overtake him.

pre-20th century: Leaving Marx aside, it's Smith, no question. Alfred Marshall and David Ricardo are possibilities, but neither ranks near Smith.

If we're talking influential economists with an influence through economics and not simply through policy couched in economic terms (leaving out Malthus and Marx) -- a non-obvious candidate would be Cournot.

After all he pioneered the graphical demand curve, standard monopoly analysis, oligopoly analysis, rudimentary game theory, and arguably Cournot's work is the only work in the pre-Walrasian age which resembles what is now the standard micro core.

Pre 20th Century: Smith.

20th Century: At least one vote for Samuelson.

Pre-20th: Walras, Marshall, Mill, Smith, Marx, Malthus...all good picks, but mine is a toss-up between David Ricardo and Thomas Munn.

Ricardo's thoughts and work on the productivity of English farming really laid the ground work for the entire marginal revolution, which we all know makes economics work.

Munn I've always thought of as sort of the father of mercantilism. And, just looking around the world today, it's obvious the mercantilism is quite well thought of in many places.

Neither is particularly famous, but influence is different than fame.

20th Century: I'm going to have to go with Maynard Keynes, hands down. His ideas might've been pretty bad, on balance, but there's no question that he was the most influential. All western governments use Keynesian maneuvers, even supposed "conservatives". Bush's tax cuts and spending increase during recession are exactly what a Keynesian would order.

It seems to me that "most influential" should go to the person whose ideas had the greatest impact. The impact of Marx was almost wholly political. When I tell my Marxist colleagues in the humanities that Marx's economics was nonsense, they say it doesn't matter (of course, it mattered to him!), that his important insights were philosophical or social.

For world changing insights, there seem to be 2 of utmost importance--Smith's "hidden hand" and second, marginal utility theory. The latter, if I recall correctly, was developed almost simultaneously by Menger, Jevons and Walras. And all three were building on insights by Ricardo. I haven't read Marshall, but I am under the impression that he put all of this stuff together and taught it to generations of economists. So Smith has to be first, with any of the others second.

As for the 20th century, it has to be Keynes. Keynes begat Samuelson, and on to the n-th generation. When I open a contemporary econ textbook, I still find it dominated by Keynes.

Yeah, but Kepler had it easy. Copernicus was labeled a heretic. The Enlightenment does not start without a bunch of things (printing press, circumnavigation of the globe, etc.). Copernicus came from the ranks of the church. He observed that the teachings didn't jibe with reality. He called them on it and broke their monopoly. He made the world safe for Isaac Newton more than a century later.

I'd say it's a toss-up between Lord Keynes and Hayek. If I was forced to choose, I'd say Keynes, by a whisker.

Brad Hutchings writes:

"Copernicus was labeled a heretic. ... He made the world safe for Isaac Newton more than a century later."

This is not so:

Copernicus, Nicolaus (Sheila Rabin), Stanford Encyclopedia of Philosophy
Sec. 2.6 Sixteenth Century Reactions to On the Revolutions:

"Thus, in 1600 there was no official Catholic position on the Copernican system, and it was certainly not a heresy. When Giordano Bruno (1548-1600) was burned at the stake as a heretic, it had nothing to do with his writings in support of Copernican cosmology."

The astronomy of Ptolemy was not a teaching of the Catholic Church. Copernicus' difficulties were exclusively intellectual, which were resolved by Kepler. Do Not conflate Galileo with Copernicus. Newton of course lived in a Protestant and relatively tolerant country 140 years later, the Catholic Church presented him with no obstacles at all.

John Stuart Mill and David Riccardo are up there on my list of most influential economists. One helped fight slavery and the other established the single economic theory that cannot be easily challenged (at least where politics are not involved).