TO DO

Resume the big book on the history of equilibrium
Resume the two articles from Mark Blaug on the Marginalist revolution and Theoretical revolution of the 1950s
Resume the article from Veblen

Statement of purpose

Without much depth of view of the different historic periods, we wanted to write a text that would bring, to a non specialist person interested in the challenges of economics, a historical view of one of the subjects submitted to harsh critics lately in the name of : economic equilibrium. We hope that with this historical recall, the reader will be more inclined to rephrase and contextualize the critics that can be made to the current state of economics.

Introduction

Since 2008, there has been a resurgence of critics made on economics. On the public side there has been huge gatherings of people such as the Occupy movement in the US and the movement "Les Indignés" which took place in Spain, starting 2011. On the academic side their has also been huge critics of the current orthodox workflow of economics. In 2008, J-P Bouchaud in his article titled : "The (unfortunate) complexity of the economy" \cite{Bouchaud_2009} wrote a critical account of the current economic theory. On the concept of equilibrium and the concept of an agent with rational expectations trying to optimize his behaviour with respect to the others (which is a common way things are studied in economics today), he says essentially that we know that complex systems can exhibit an extremely large number of minima, meaning that the agent will essentially need an infinite time to find his optimal behaviour and that society might never settle at the supposed equilibrium. He also points out the difficulty to empirically prove the assumption about the rational expectations of the individual agents as people very rarely optimize their behaviour in their day-to-day life.
From a methodological point of view, having explained the importance of the notion of equilibrium in economics today, this article aims to discuss the relevance of the notion of equilibrium, in which situations it may or may not be useful. It will then present in greater details the shortcomings of the theory of general equilibrium. Through a "historiographical approach" (as defined by Mark Blaug in \cite{Blaug_1990}--> décrire exactement quelle est sa définition, qu'ai-je voulu dire par là ?) we will then try to understand what were the conditions of emergence of this notion of equilibrium, helping us to see how fundamental the notion of equilibrium and how it was socially constructed (to use the terminology of Bruno Latour, see \cite{latour1986laboratory} in a biology context).

Quick description of equilibrium theory

General equilibrium, how is it used.

How important is the notion of equilibrium in economics today

As shown in the introduction and as we found out during our research, one concept that stood out was the notion of equilibrium. In this section we will try to understand why this notion of equilibrium is such an important feature of today's economic theory.
Describe how relevant it is today and why it is not a research subject anymore, according to \cite{Israel2015}, but \cite{Farmer_2009} still thinks that it is still a very used framework of thought.
According to \cite{Farmer_2009}, the notion of equilibrium is very well still in use in mainstream economics today, the utility function and the rational expectations paradigm are still a framework of reference for many economists. In macroeconomics, the use of the representative agent (modeling the behaviour of all the different supposed-rational agents by a single "representative agent") is a common paradigm that has been criticized by \cite{Bouchaud_2009}, using an analogy with complex physical systems that not behave like a single atom or electron, they can exhibit very strange phase-transition patterns that must surely also arise in economic systems. 
Debreu --> Nobel lecture and article of 1954 \cite{1}. Very interesting because he even gives the way of how he came to think the way he did. Moreover, he does not make any grandiloquent assumption about the way an economy should work (to be nuanced because he seems to think that his theorems do apply). In the introduction he talks about Cournot as the founder of mathematical economics and Walras and Pareto as the two other main figure of mathematical economics. He also discloses that he was under the huge impact of Bourbaki and of his professors at the Ecole Normale Supérieure in France where he was a student of mathematics. 
The last paragraph of his work looks even special, he seems to have done the historians job : "In narratives of their careers, scientists try to acknowledge the main influences to which they responded, and the support they received from other scientists and from different institutions, even though such attempts are unlikely to be entirely successful. To all the persons and organizations I have named, I want to add the outstanding education system I have known in France, and the Centre National de la Recherche Scientifique which made my conversion from mathematics to economics possible. After my move to the United States in 1950, I was associated with three great universities (Chicago, Yale, and Berkeley) where scientific research is a natural way of life; and during the last two decades the Economics Program of the National Science Foundation has given me, more than anything else, time for that research. All those institutions have provided a superb environment for the task that had to be performed."

How useful is the notion of equilibrium ?

Principally the article from Farmer.
\cite{Farmer_2009} extremely interesting article. Written by a physicist and an economist who have worked in finance (plus Doyne Farmer is an amazing scientist), and have confronted the notion of equilibrium to real markets. They start by defining what is an equilibrium, how it is attained, how it is used in practice and then discuss empirical evidence on its foundations. They also discuss the reasons to look for out-of-equilibrium models
Series of quotes from the article:
As the conclusion of the article : "We have written this articles with a dual purpose. On one hand we worry that physicists often misunderstand the equilibrium framework in economics, and fail to appreciate the very good reasons for its emergence. On the other hand, the majority of economists have become so conditioned to explain everything in terms of equilibrium that they do not appreciate that there are many circumstances in which this is unlikely to be appropriate."
The second to last sentence is particularly interesting : "It can be criticized, though, as a quick and dirty method, a heroic attempt to simplify a complex problem."

Shortcomings of the notion of equilibrium

Principally articles from Kirman
Among the various citations that we can get from Alan Kirman's article, we should talk about the notion of that they do not describe reality as in his example of the Marseille fish market.
In his 2016 article titled: "The Trouble with Macroeconomics" Paul Romer \cite{romer2016} made a parallel between the development of macroeconomics in the past thirty years and the one of string theory in theoretical high-energy physics. By calling many theoreticians of macroeconomics, post-real economists he displays a severe critic of the way macroeconomics works. The lackings he identified are: