<p>There is a difference between the 3 concepts. They should not be used interchangeably in rigorous explanations and textbooks such as Mankiw's Principles of Economics do not use these words interchangeably.</p>
<p><strong>Demand</strong></p>
<p>Demand typically refers to the whole demand relationship between price and quantity demanded. If you are asked to plot supply &amp; demand or just demand you are asked to produce graph of demand function.</p>
<p>So a demand can be given by:</p>
<p><span class="math-container">$$Q_d= 100-P \tag{1} $$</span></p>
<p>and the above would be demand. More graduate sources will typically also say 'demand function' but even in graduate textbooks such as Varian Microeconomic Analysis 3rd ed ch 9 will refer commonly to demand functions as just demand.</p>
<p><strong>Quantity Demanded</strong></p>
<p>This is some specific quantity demanded. It is a point along the demand function but not the whole function.</p>
<p>For example, continuing to use eq. 1 if price is 10 <em>quantity</em> demanded would be 90.</p>
<p>So the quantity demanded is some specific value for a function. It does not need to be explicit number. For example, <span class="math-container">$Q^*$</span> can be the equilibrium quantity demanded. The point is that quantity demanded will be some particular point given by the demand curve at some particular price.</p>
<p><strong>Demand Schedule</strong></p>
<p>Demand schedule is a particular way how to capture whole demand. It is analogue to demand 'graph'.</p>
<p>Below you can see an example of demand schedule from Mankiw's Principles pp 120. As you can see demand schedule is a way how to also capture demand function by putting it in a table or in another words schedule.</p>
<p><a href="https://i.sstatic.net/pDqPo.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/pDqPo.jpg" alt="enter image description here" /></a></p>
<hr />
<blockquote>
<p>Also, is there a difference between shift in demand and increase in demand?</p>
</blockquote>
<p>No as far as I can see or if there is any difference even textbooks mistakenly use them interchangeably. For example, on pp 305 Mankiw refers to graph that shows shift of demand function as an increase in demand.</p>
<p>However, one needs to be very careful here because increase in <em>quantity</em> demanded would be just change along demand curve (that is just change in quantity demanded as a response to price change) not shift of the demand curve (which means quantity demanded changes at every possible price), but I think I seen sources that are not so careful with terminology.</p>
<hr />
<p><strong>Where the Confusion Probably Comes From</strong></p>
<p>Some of the confusion might stem from loose use of this terminology outside profession.</p>
<p>In media people sometimes use word demand as a shorthand for quantity demanded.</p>
<p>This usage is however incorrect, in economics it is clearly important to distinguish between demand and quantity demanded especially the distinction is important in supply demand analysis.</p>
<hr />
<p>PS: I teach econ 101 to undergraduates and I can concur that students often make mistakes between quantity demanded and demand.</p>
<p>However, I did not have many students who would be confused about demand schedule.</p>

CC BY-SA 4.0
2022-02-09T10:56:40.907Z
I find "*point along demand function*" is somewhat unfortunate phrasing. Aside from the Russian anti-article agenda (: the problem is that a point is two dimensional, but quantity demanded is not.
Giskard
CC BY-SA 4.0
2022-02-09T10:58:57.913Z
@Giskard huh? Points are zero dimentional https://en.wikipedia.org/wiki/Point_(geometry)#:~:text=Dimension%20of%20a%20point,-There%20are%20several&text=In%20all%20of%20the%20common,a%20point%20is%200%2Ddimensional.
1muflon1
CC BY-SA 4.0
2022-02-09T10:59:43.107Z
Okay, then let's say a point is a tuple, while quantity demanded is a real number.
Giskard
CC BY-SA 4.0
2022-02-09T10:59:56.290Z
@Giskard I changed phrasing
1muflon1
CC BY-SA 4.0
2022-02-09T11:01:39.017Z
I think this answer is not very accessible to beginners, it could benefit from explaining the concept "*along demand curve*"  more clearly. I.e. quantity demanded is the value $D$ takes given a certain price (and other parameters), change along the demand curve means the curve is unchanged, but price changes, and hence $q$ demanded changes as well, etc. Perhaps providing a bad and good example of usage in each case.
Giskard
CC BY-SA 4.0
2022-02-09T11:03:49.937Z
@Giskard I added an extra expiation for both movement along demand curve and shift in demand
1muflon1
CC BY-SA 4.0
2022-02-09T13:36:48.357Z
"Demand typically refers to the whole demand relationship ...".  That may be correct when the term is used by economists, but in more general usage "demand" often refers to quantity demanded.  See for example [this report by the International Energy Agency](https://www.iea.org/reports/oil-market-report-december-2021) making statements such as "Global oil demand is now set to rise by 5.4 mbd in 2021".
Adam Bailey
CC BY-SA 4.0
2022-02-09T13:42:36.707Z
@AdamBailey right but this is economics site, rationality has also different usage in common English, and most economic terms do. Most people call money capital, call income reported in accounting profit etc… I believe Giskard was looking for economic answer not for an answer that would cover layman’s misuses of the economic terminology
1muflon1
CC BY-SA 4.0
2022-02-09T21:01:25.517Z
I think @AdamBailey makes a good point. Students of economics may not know that the lay language differs. I added the `nonexpert` tag to the question, so a good answer should address this.
Giskard
CC BY-SA 4.0
2022-02-09T21:31:41.210Z
@Giskard ok I addressed it in separate section
1muflon1
CC BY-SA 4.0
2022-02-09T10:47:01.963Z
2022-02-09T21:31:23.393Z
2022-02-09T21:31:23.393Z
1muflon1
<p>What is the difference between the concepts of <em>demand</em>, <em>demand schedule</em> and <em>quantity demanded</em>?</p>
<p>Can these be used interchangeably, and do any of them have multiple meanings in economics?</p>
<p>Also, is there a difference between <em>shift</em> in demand and <em>increase</em> in demand?</p>
<hr />
<p>To see how these concepts are frequently confusing students, see the questions</p>
<p><a href="https://economics.stackexchange.com/q/36945/1601">What is the difference between the demand schedule and the demand curve?</a></p>
<p><a href="https://economics.stackexchange.com/q/22261/1601">Demand curve confusion</a></p>

<nonexpert><definition><demand>
Demand vs. demand schedule vs. quantity demanded
Giskard
# Demand vs. demand schedule vs. quantity demanded

(Asked by: username_0 on 2022-02-09)

What is the difference between the concepts of *demand*, *demand schedule* and *quantity demanded*?

Can these be used interchangeably, and do any of them have multiple meanings in economics?

Also, is there a difference between *shift* in demand and *increase* in demand?

---

To see how these concepts are frequently confusing students, see the questions

[What is the difference between the demand schedule and the demand curve?](https://economics.stackexchange.com/q/36945/1601)

[Demand curve confusion](https://economics.stackexchange.com/q/22261/1601)

**Tags:** nonexpert, definition, demand

---

## 1 answers

### Answer by username_1 on 2022-02-09. Score: 1

There is a difference between the 3 concepts. They should not be used interchangeably in rigorous explanations and textbooks such as Mankiw's Principles of Economics do not use these words interchangeably.

**Demand**

Demand typically refers to the whole demand relationship between price and quantity demanded. If you are asked to plot supply & demand or just demand you are asked to produce graph of demand function.

So a demand can be given by:

$$Q\_d= 100-P \tag{1} $$

and the above would be demand. More graduate sources will typically also say 'demand function' but even in graduate textbooks such as Varian Microeconomic Analysis 3rd ed ch 9 will refer commonly to demand functions as just demand.

**Quantity Demanded**

This is some specific quantity demanded. It is a point along the demand function but not the whole function.

For example, continuing to use eq. 1 if price is 10 *quantity* demanded would be 90.

So the quantity demanded is some specific value for a function. It does not need to be explicit number. For example, $Q^\*$ can be the equilibrium quantity demanded. The point is that quantity demanded will be some particular point given by the demand curve at some particular price.

**Demand Schedule**

Demand schedule is a particular way how to capture whole demand. It is analogue to demand 'graph'.

Below you can see an example of demand schedule from Mankiw's Principles pp 120. As you can see demand schedule is a way how to also capture demand function by putting it in a table or in another words schedule.

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

---

> Also, is there a difference between shift in demand and increase in demand?

No as far as I can see or if there is any difference even textbooks mistakenly use them interchangeably. For example, on pp 305 Mankiw refers to graph that shows shift of demand function as an increase in demand.

However, one needs to be very careful here because increase in *quantity* demanded would be just change along demand curve (that is just change in quantity demanded as a response to price change) not shift of the demand curve (which means quantity demanded changes at every possible price), but I think I seen sources that are not so careful with terminology.

---

**Where the Confusion Probably Comes From**

Some of the confusion might stem from loose use of this terminology outside profession.

In media people sometimes use word demand as a shorthand for quantity demanded.

This usage is however incorrect, in economics it is clearly important to distinguish between demand and quantity demanded especially the distinction is important in supply demand analysis.

---

PS: I teach econ 101 to undergraduates and I can concur that students often make mistakes between quantity demanded and demand.

However, I did not have many students who would be confused about demand schedule.

> **Comments:**
> **username_0**: I find "*point along demand function*" is somewhat unfortunate phrasing. Aside from the Russian anti-article agenda (: the problem is that a point is two dimensional, but quantity demanded is not.  
> **username_1**: @Giskard huh? Points are zero dimentional https://en.wikipedia.org/wiki/Point_(geometry)#:~:text=Dimension%20of%20a%20point,-There%20are%20several&text=In%20all%20of%20the%20common,a%20point%20is%200%2Ddimensional.  
> **username_0**: Okay, then let's say a point is a tuple, while quantity demanded is a real number.  
> **username_1**: @Giskard I changed phrasing  
> **username_0**: I think this answer is not very accessible to beginners, it could benefit from explaining the concept "*along demand curve*"  more clearly. I.e. quantity demanded is the value $D$ takes given a certain price (and other parameters), change along the demand curve means the curve is unchanged, but price changes, and hence $q$ demanded changes as well, etc. Perhaps providing a bad and good example of usage in each case.  
> **username_1**: @Giskard I added an extra expiation for both movement along demand curve and shift in demand  
> **username_2**: "Demand typically refers to the whole demand relationship ...".  That may be correct when the term is used by economists, but in more general usage "demand" often refers to quantity demanded.  See for example [this report by the International Energy Agency](https://www.iea.org/reports/oil-market-report-december-2021) making statements such as "Global oil demand is now set to rise by 5.4 mbd in 2021".  
> **username_1**: @AdamBailey right but this is economics site, rationality has also different usage in common English, and most economic terms do. Most people call money capital, call income reported in accounting profit etc… I believe Giskard was looking for economic answer not for an answer that would cover layman’s misuses of the economic terminology  
> **username_0**: I think @AdamBailey makes a good point. Students of economics may not know that the lay language differs. I added the `nonexpert` tag to the question, so a good answer should address this.  
> **username_1**: @Giskard ok I addressed it in separate section  

---

