<p>Public goods are goods which have a fixed cost and are sometimes free for businesses. Think of police. They patrol streets, protecting businesses premises. Businesses do not pay directly for these services, except in very general terms with taxation and land rates. But these are fixed costs in the sense that the provision of the service do not depend on the activities of the firm.</p>

CC BY-SA 3.0
2017-11-04T11:26:38.027Z
2017-11-04T11:26:38.027Z
Robert_T
<p>Air is a complement good for a lot of things. If you get no air at all then food, gold and iPhones give you no utility either. And air is free! Except in <a href="https://www.youtube.com/watch?v=gzbIrb7LUJA" rel="nofollow noreferrer">Spaceballs</a>...</p>

CC BY-SA 3.0
2017-11-03T22:56:14.677Z
I believe there is a typo in your second sentence. Also can't tell if you are being sarcastic.
William
CC BY-SA 3.0
2017-11-03T22:59:44.297Z
What about gravity?  Bikes, cars, and even air wouldn't be much good without gravity.
Hot Licks
CC BY-SA 3.0
2017-11-04T09:30:42.383Z
@William Thanks, corrected the typo. As for sarcasm: I am not sure what you mean. The first three sentences are trivially true. Referencing the Spaceballs movie is a joke, you can put that aside. If this does not answer your question then I am afraid I do not understand your question. (Which itself seems to contain an example - the ARPANET - that has a fixed cost.)
Giskard
CC BY-SA 3.0
2017-11-04T09:31:34.077Z
@HotLicks Pretty sure the austronauts aboard the ISS enjoy their air even without gravity, but hey, you can also post gravity as an answer!
Giskard
CC BY-SA 3.0
2017-11-03T22:16:27.507Z
2017-11-04T09:29:11.027Z
2017-11-04T09:29:11.027Z
Giskard
<p>I was not around at this time but I know roads(existing for bikes) and gas(existing for tractors) were complements for cars.</p>

<p>I was looking at complements for computers and noticed the ARPANET could maybe be regarded as a complement because it appears it would increase a computers usefulness.  I'm trying to leave the history out of this but I figured an example would be helpful.</p>

<p>Can a complement good like the ARPANET have either a fixed cost or be free?</p>

<perfect-complements>
Can a complement good be free or have a fixed cost?
William
# Can a complement good be free or have a fixed cost?

(Asked by: username_0 on 2017-11-03)

I was not around at this time but I know roads(existing for bikes) and gas(existing for tractors) were complements for cars.

I was looking at complements for computers and noticed the ARPANET could maybe be regarded as a complement because it appears it would increase a computers usefulness. I'm trying to leave the history out of this but I figured an example would be helpful.

Can a complement good like the ARPANET have either a fixed cost or be free?

**Tags:** perfect-complements

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## 2 answers

### Answer by username_2 on 2017-11-03. Score: 3 | Accepted answer

Air is a complement good for a lot of things. If you get no air at all then food, gold and iPhones give you no utility either. And air is free! Except in [Spaceballs](https://www.youtube.com/watch?v=gzbIrb7LUJA)...

> **Comments:**
> **username_0**: I believe there is a typo in your second sentence. Also can't tell if you are being sarcastic.  
> **username_3**: What about gravity?  Bikes, cars, and even air wouldn't be much good without gravity.  
> **username_2**: @William Thanks, corrected the typo. As for sarcasm: I am not sure what you mean. The first three sentences are trivially true. Referencing the Spaceballs movie is a joke, you can put that aside. If this does not answer your question then I am afraid I do not understand your question. (Which itself seems to contain an example - the ARPANET - that has a fixed cost.)  
> **username_2**: @HotLicks Pretty sure the austronauts aboard the ISS enjoy their air even without gravity, but hey, you can also post gravity as an answer!  

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### Answer by username_1 on 2017-11-04. Score: 2

Public goods are goods which have a fixed cost and are sometimes free for businesses. Think of police. They patrol streets, protecting businesses premises. Businesses do not pay directly for these services, except in very general terms with taxation and land rates. But these are fixed costs in the sense that the provision of the service do not depend on the activities of the firm.


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