# What are the fundamental theorems of welfare economics? [closed]

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

## closed as too broad by Thorst, EnergyNumbers, Lumi, BKay, FooBarMar 6 '15 at 20:53

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• Different results are based on different assumptions. Any specific results you have in mind? – Pburg Nov 24 '14 at 2:32
• @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 Nov 24 '14 at 2:53
• 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 Nov 24 '14 at 3:31
• 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 Nov 24 '14 at 4:27
• 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 Nov 24 '14 at 5:58

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.