<p>Perhaps you have heard the competitive equilibrium referred to as the Arrow-Debreu equilibrium.</p>

<p>The idea of the theorems existed earlier but Arrow introduced the theorems formally in a way that is equivalent to what we today call the first and second welfare theorem in 1951 in his paper</p>

<p><a href="http://projecteuclid.org/download/pdf_1/euclid.bsmsp/1200500251" rel="noreferrer">AN EXTENSION OF THE BASIC
THEOREMS OF CLASSICAL
WELFARE ECONOMICS</a>.</p>

<p>Debreu is more associated with proving that the equilibrium exists under certain conditions. If you think about it this makes the first welfare theorem much stronger. His seminal paper on the subject is</p>

<p><a href="http://www.jstor.org/stable/pdf/1906814.pdf" rel="noreferrer">The Coefficient of Resource Utilization</a>.</p>

CC BY-SA 3.0
2016-03-29T04:44:44.260Z
Arrow's paper is called "an extension", indicating that those theorems already existed. Are Arrow and Debreu really the two that introduced them originally?
B T
CC BY-SA 3.0
2016-03-29T04:57:51.640Z
This article seems to say that Kenneth Arrow first proved the First and Second theorems, but that Debreu proved that a general equilibrium is reached under certain conditions http://www.econlib.org/library/Enc/bios/Arrow.html . Am I understanding this right?
B T
CC BY-SA 3.0
2016-03-29T08:58:52.333Z
@BT The idea of the theorems existed earlier but Arrow introduced the theorems formally in a way that is equivalent to what we today call the first and second welfare theorem. Debreu is indeed more associated with proving that the equilibrium exists under certain conditions. If you think about it this makes the first welfare theorem much stronger.
Giskard
CC BY-SA 3.0
2016-03-29T13:39:26.747Z
@denesp I think your comment would fit nicely into the answer :)
FooBar
CC BY-SA 4.0
2021-06-25T05:31:03.787Z
Actually, the usual textbook version with local non-satiation is due to Koopmans. Arrow assumed strong convexity instead.
Michael Greinecker
CC BY-SA 3.0
2016-03-29T03:42:58.827Z
2016-03-29T18:41:19.587Z
2016-03-29T18:41:19.587Z
Giskard
<p>What years and by who were the first and second welfare theorems first proven?</p>

CC BY-SA 3.0
2016-03-29T18:08:29.430Z
Why the downvote?
B T
CC BY-SA 3.0
2016-03-29T18:39:35.133Z
Unfortunately whoever downvoted it gets no message when you comment so it is unlikely they will answer. But if you like getting feedback please consider accepting answers to some of your [older](http://economics.stackexchange.com/questions/9023/how-much-do-real-estate-prices-correlate-with-apartment-rental-prices) [questions](http://economics.stackexchange.com/questions/11104/what-are-examples-of-natural-monopolies-that-dont-have-overwhelming-economies-o).
Giskard
<microeconomics><welfare-economics>
When were the First and Second Welfare Theorems proven?
B T
# When were the First and Second Welfare Theorems proven?

(Asked by: username_0 on 2016-03-29)

What years and by who were the first and second welfare theorems first proven?

**Tags:** microeconomics, welfare-economics

> **Comments:**
> **username_0**: Why the downvote?  
> **username_1**: Unfortunately whoever downvoted it gets no message when you comment so it is unlikely they will answer. But if you like getting feedback please consider accepting answers to some of your [older](http://economics.stackexchange.com/questions/9023/how-much-do-real-estate-prices-correlate-with-apartment-rental-prices) [questions](http://economics.stackexchange.com/questions/11104/what-are-examples-of-natural-monopolies-that-dont-have-overwhelming-economies-o).  

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## 1 answers

### Answer by username_1 on 2016-03-29. Score: 6 | Accepted answer

Perhaps you have heard the competitive equilibrium referred to as the Arrow-Debreu equilibrium.

The idea of the theorems existed earlier but Arrow introduced the theorems formally in a way that is equivalent to what we today call the first and second welfare theorem in 1951 in his paper

[AN EXTENSION OF THE BASIC
THEOREMS OF CLASSICAL
WELFARE ECONOMICS](http://projecteuclid.org/download/pdf_1/euclid.bsmsp/1200500251).

Debreu is more associated with proving that the equilibrium exists under certain conditions. If you think about it this makes the first welfare theorem much stronger. His seminal paper on the subject is

[The Coefficient of Resource Utilization](http://www.jstor.org/stable/pdf/1906814.pdf).

> **Comments:**
> **username_0**: Arrow's paper is called "an extension", indicating that those theorems already existed. Are Arrow and Debreu really the two that introduced them originally?  
> **username_0**: This article seems to say that Kenneth Arrow first proved the First and Second theorems, but that Debreu proved that a general equilibrium is reached under certain conditions http://www.econlib.org/library/Enc/bios/Arrow.html . Am I understanding this right?  
> **username_1**: @BT The idea of the theorems existed earlier but Arrow introduced the theorems formally in a way that is equivalent to what we today call the first and second welfare theorem. Debreu is indeed more associated with proving that the equilibrium exists under certain conditions. If you think about it this makes the first welfare theorem much stronger.  
> **username_2**: @denesp I think your comment would fit nicely into the answer :)  
> **username_3**: Actually, the usual textbook version with local non-satiation is due to Koopmans. Arrow assumed strong convexity instead.  

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