<p>A recently published (and perhaps the only one) paper on the matter is</p>

<p><a href="http://hope.dukejournals.org/content/44/4/643.short" rel="nofollow noreferrer"><strong>Lloyd, P. (2012). The Discovery of the Isoquant. History of Political Economy, 44(4), 643-661.</strong></a></p>

<p>From the Introduction :</p>

<blockquote>
  <p><em>"The absence of a history of the isoquant is in marked contrast to the universal recognition that F. Y. Edgeworth (1881) invented the
  concept of the indifference curve. It turns out that the isoquant does
  have an interesting history of multiple discoveries or apparent
  discoveries. Section 1 outlines the first appearances of the isoquant,
  as far as I have been able to trace them, in chronological order. The
  contributions of two originators, namely, A. L. Bowley and Charles W.
  Cobb, seem not to have been noted before. Section 2 discusses the
  obvious question of why the discovery of the isoquant was not made
  until more than forty years after the discovery of the indifference
  curve, when to a modern analyst the isoquant appears isomorphic to the
  indifference curve and could have been copied straight from utility
  theory."</em></p>
</blockquote>

<p>In Section 1 we read (p.645)</p>

<blockquote>
  <p><em>"The first unquestionable appearance of isoquants is in Bowley 1924"</em></p>
</blockquote>

<p><strong>(Bowely, A. L. 1924. The Mathematical Groundwork of Economics: An Introductory Treatise. Oxford: Clarendon Press)</strong></p>

<p>Lloyd reproduces the figure to be found in Bowley:</p>

<p><a href="https://i.sstatic.net/MX7uN.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/MX7uN.png" alt="enter image description here"></a></p>

<p>As for the term "isoquant" Lloyd writes</p>

<p><em>"In his second note on the elasticity of substitution in the same
journal, Lerner (1934) called the curve the “isoquant.” This is one of the
first uses of the term isoquant in the English-language literature.</em>"</p>

<p><strong>(Lerner A.P. 1934. “Notes on Elasticity of Substitution II.” Review of Economic Studies 1(2): 147–48.)</strong></p>

<p>As regards the question "why isoquants took so long after the indiferrence curves invention", from the three possible (and not antagonistic) explanations that Lloyd puts forward I find very interesting the third one: in his words (p. 658) (bold my emphasis)</p>

<blockquote>
  <p><em>"Following the practice of the English classical writers, <strong>all</strong> neoclassical writers on production and distribution theory
  distinguished a <strong>trilogy of factors—land, labor, and capital</strong>."</em></p>
</blockquote>

<p>So if your mind is fixed to thinking <em>three</em> inputs, (and a very realistic triplet at that), you won't go easily into thinking just two of them  -and realize that you can represent them graphically.</p>

CC BY-SA 3.0
2016-05-02T23:44:20.237Z
2016-05-02T23:50:07.520Z
2016-05-02T23:50:07.520Z
Alecos Papadopoulos
<p>I was wondering if anyone had an idea about the first author to have mathematically computed an isoquant or at least the first occurrence of a drawn isoquant ? My best guess would be F. Edgeworth in <em>Mathematical Psychics: An Essay on the Application of Mathematics to the Moral Sciences</em> (1881) but I really doubt it !</p>

CC BY-SA 3.0
2016-04-29T18:30:38.940Z
Did you mean who coined the term *isoquant*, or the first person who came up with the idea of using a set of two-dimensional curves to represent the level in the third dimension?
Herr K.
CC BY-SA 3.0
2016-04-29T22:49:46.163Z
The person who forged the term. Eventhough I think this very person also illustrated his neologism with the 3 dimensional curve !
Alexis L.
<microeconomics><history-economic-thought>
Isoquant creator
Alexis L.
# Isoquant creator

(Asked by: username_0 on 2016-04-29)

I was wondering if anyone had an idea about the first author to have mathematically computed an isoquant or at least the first occurrence of a drawn isoquant ? My best guess would be F. Edgeworth in *Mathematical Psychics: An Essay on the Application of Mathematics to the Moral Sciences* (1881) but I really doubt it !

**Tags:** microeconomics, history-economic-thought

> **Comments:**
> **username_1**: Did you mean who coined the term *isoquant*, or the first person who came up with the idea of using a set of two-dimensional curves to represent the level in the third dimension?  
> **username_0**: The person who forged the term. Eventhough I think this very person also illustrated his neologism with the 3 dimensional curve !  

---

## 1 answers

### Answer by username_2 on 2016-05-02. Score: 4 | Accepted answer

A recently published (and perhaps the only one) paper on the matter is

[**Lloyd, P. (2012). The Discovery of the Isoquant. History of Political Economy, 44(4), 643-661.**](http://hope.dukejournals.org/content/44/4/643.short)

From the Introduction :

> *"The absence of a history of the isoquant is in marked contrast to the universal recognition that F. Y. Edgeworth (1881) invented the
> concept of the indifference curve. It turns out that the isoquant does
> have an interesting history of multiple discoveries or apparent
> discoveries. Section 1 outlines the first appearances of the isoquant,
> as far as I have been able to trace them, in chronological order. The
> contributions of two originators, namely, A. L. Bowley and Charles W.
> Cobb, seem not to have been noted before. Section 2 discusses the
> obvious question of why the discovery of the isoquant was not made
> until more than forty years after the discovery of the indifference
> curve, when to a modern analyst the isoquant appears isomorphic to the
> indifference curve and could have been copied straight from utility
> theory."*

In Section 1 we read (p.645)

> *"The first unquestionable appearance of isoquants is in Bowley 1924"*

**(Bowely, A. L. 1924. The Mathematical Groundwork of Economics: An Introductory Treatise. Oxford: Clarendon Press)**

Lloyd reproduces the figure to be found in Bowley:

[![enter image description here](https://i.sstatic.net/MX7uN.png)](https://i.sstatic.net/MX7uN.png)

As for the term "isoquant" Lloyd writes

*"In his second note on the elasticity of substitution in the same
journal, Lerner (1934) called the curve the “isoquant.” This is one of the
first uses of the term isoquant in the English-language literature.*"

**(Lerner A.P. 1934. “Notes on Elasticity of Substitution II.” Review of Economic Studies 1(2): 147–48.)**

As regards the question "why isoquants took so long after the indiferrence curves invention", from the three possible (and not antagonistic) explanations that Lloyd puts forward I find very interesting the third one: in his words (p. 658) (bold my emphasis)

> *"Following the practice of the English classical writers, **all** neoclassical writers on production and distribution theory
> distinguished a **trilogy of factors—land, labor, and capital**."*

So if your mind is fixed to thinking *three* inputs, (and a very realistic triplet at that), you won't go easily into thinking just two of them -and realize that you can represent them graphically.


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