<p>I presume you meant <a href="http://en.wikipedia.org/wiki/Fundamental_theorems_of_welfare_economics" rel="nofollow noreferrer">The Fundamental Theorems</a>:</p>
<blockquote>
<p>The first fundamental theorem of welfare economics states that any Walrasian equilibrium is Pareto-efficient.</p>
<p>The second fundamental theorem of welfare economics states that, under the assumptions that every production set <span class="math-container">$Y_j$</span> is convex and every preference relation <span class="math-container">$\geq _i$</span> is convex and locally nonsatiated, any desired Pareto-efficient allocation can be supported as a price quasi-equilibrium with transfers. Further assumptions are needed to prove this statement for price equilibriums with transfers.</p>
</blockquote>
<p>Or you could read <a href="http://www.nber.org/papers/w3641.pdf" rel="nofollow noreferrer">Stiglitz's Paper</a> yourself if you were so inclined.</p>

CC BY-SA 3.0
2014-11-24T15:45:34.013Z
These fundamental theorems have some assumptions behind them, which is what I am trying to get at with my question.  I will edit my question when I get back to my desk to make this more clear.
Alex
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2014-11-24T15:47:55.000Z
Ah yes I see the question has been changed.  I will instead ask another question refering to this one.
Alex
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2014-11-24T03:22:07.100Z
2014-11-24T03:22:07.100Z
2020-06-17T09:40:54.643Z
Jason Nichols
<p>All of welfare economics is based on some theorems, some of which I can remember, but I am looking for a comprehensive list.</p>

CC BY-SA 3.0
2014-11-24T02:32:30.793Z
Different results are based on different assumptions. Any specific results you have in mind?
Pburg
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2014-11-24T02:53:26.230Z
@Pburg I think he's referring to the fundamental assumptions of the sub-discipline itself. I'm no welfare economist, but I would think some assumptions are that utility can only be ordinal and not cardinal (in analysis). That we cannot do an interperson comparison of utility. That pareto improvements are preferred over kaldor-hicks improvements. So on and so forth. I'm really just guessing though.
rosenjcb
CC BY-SA 3.0
2014-11-24T03:31:19.250Z
Voting to close as too broad. Welfare economics covers many things and there isn't a single set of assumptions that applies to the whole area.
Jyotirmoy Bhattacharya
CC BY-SA 3.0
2014-11-24T04:19:46.950Z
Close voters, please note, my suggested edit was accepted, and it radically alters the question. May still not be up to snuff, but is certainly not too broad anymore. Also, please suggest edits if you can.
Jason Nichols
CC BY-SA 3.0
2014-11-24T04:27:52.043Z
I deleted my answer which was not appropriate anymore following you edit, but I would still be careful with claims like "All of welfare economics is based on some theorems".
Martin Van der Linden
CC BY-SA 3.0
2014-11-24T05:58:31.167Z
This does seem like a very broad question. It may be helpful if you comment on the one posted answer (at the time of this comment) from @Jason Nichols, about the two Fundamental Welfare Theorems which I suspect many PhD economists will think of immediately. If these are not what you have in mind, it would be good to know.
CompEcon
CC BY-SA 3.0
2014-11-24T15:43:54.900Z
Hello, yes I am looking for the assumption of the thereoms, I believe they are a pricing system, perfect information, no externalities and some others, but I cant find them in my old notes.  Thanks for the discussion, will comment on the answer as well.
Alex
<welfare-economics>
What are the fundamental theorems of welfare economics?
Alex
# What are the fundamental theorems of welfare economics?

(Asked by: username_0 on 2014-11-24)

All of welfare economics is based on some theorems, some of which I can remember, but I am looking for a comprehensive list.

**Tags:** welfare-economics

> **Comments:**
> **username_1**: Different results are based on different assumptions. Any specific results you have in mind?  
> **username_2**: @username_1 I think he's referring to the fundamental assumptions of the sub-discipline itself. I'm no welfare economist, but I would think some assumptions are that utility can only be ordinal and not cardinal (in analysis). That we cannot do an interperson comparison of utility. That pareto improvements are preferred over kaldor-hicks improvements. So on and so forth. I'm really just guessing though.  
> **username_3**: Voting to close as too broad. Welfare economics covers many things and there isn't a single set of assumptions that applies to the whole area.  
> **username_4**: Close voters, please note, my suggested edit was accepted, and it radically alters the question. May still not be up to snuff, but is certainly not too broad anymore. Also, please suggest edits if you can.  
> **username_5**: I deleted my answer which was not appropriate anymore following you edit, but I would still be careful with claims like "All of welfare economics is based on some theorems".  
> **username_6**: This does seem like a very broad question. It may be helpful if you comment on the one posted answer (at the time of this comment) from @username_4, about the two Fundamental Welfare Theorems which I suspect many PhD economists will think of immediately. If these are not what you have in mind, it would be good to know.  
> **username_0**: Hello, yes I am looking for the assumption of the thereoms, I believe they are a pricing system, perfect information, no externalities and some others, but I cant find them in my old notes.  Thanks for the discussion, will comment on the answer as well.  

---

## 1 answers

### Answer by username_4 on 2014-11-24. Score: 1

I presume you meant [The Fundamental Theorems](http://en.wikipedia.org/wiki/Fundamental_theorems_of_welfare_economics):

> The first fundamental theorem of welfare economics states that any Walrasian equilibrium is Pareto-efficient.
>
> The second fundamental theorem of welfare economics states that, under the assumptions that every production set $Y\_j$ is convex and every preference relation $\geq \_i$ is convex and locally nonsatiated, any desired Pareto-efficient allocation can be supported as a price quasi-equilibrium with transfers. Further assumptions are needed to prove this statement for price equilibriums with transfers.

Or you could read [Stiglitz's Paper](http://www.nber.org/papers/w3641.pdf) yourself if you were so inclined.

> **Comments:**
> **username_0**: These fundamental theorems have some assumptions behind them, which is what I am trying to get at with my question.  I will edit my question when I get back to my desk to make this more clear.  
> **username_0**: Ah yes I see the question has been changed.  I will instead ask another question refering to this one.  

---

