user715: 
What's the rationale or logic behind the precepts? 
Does fairness come into it? 
Are the list of precepts ever expanded to accommodate changing contexts?

Being very unfair to someone who trusts one is pretty similar in emotional harm to cheating on a spouse or lying, especially when the unfairness is made possible because of an abuse of a position of power. 
For example, employees of large corporations often feel lied to, even cheated when they are laid off by their employer because of new management policy. Yet, these are explicitly the terms of most employment contracts.
Similarly, a home owner can feel pretty awful when evicted by the bank or lender for failure to pay the mortgage, especially when the bank is usually writing all the rules ab-initio protecting itself from market risks. Yet, this too is an agreed upon constraint because one party operates from a position of power.
Modern life relies on governments, corporations and other faceless institutions to a large degree, and they do wield a great deal of power, so a lot of their transgressions fall afoul of the fairness test, though technically none of them are lies. This has to be a large source of misery in this world today.
Yet, going by the precepts, at least to me, such behaviour doesn't seem to be overtly criticised.
Does Buddhism have anything to say to such scenarios?

user5805: "Do not be unfair" is pretty vague. Do not lie and do not steal, those are easy recognize and not do. What is fair and unfair is subject to debate, well so are perhaps all precepts but I would say unfairness even more so. 
Who says its unfair to sack an employee? The entire system is unfair if it forces a company to sack anybody. The problem isn't with the individual, not in the scenarios you mentioned anyway. Does an economic system accumulate good and bad karma? They're not sentient so they can't follow precepts. 
Just because a home owner feels awful doesn't mean its unfair. Don't get into the game if you don't want to play, meaning don't make loans if you might not be able to pay them. 
I don't know what Buddhism has to say, but escaping the hassle of financial injustice does seem to be one of the perks of becoming a monk. Maybe the Buddha felt great leaving royal life behind and not having to concern himself with taxes, but this is just speculation. 

user-1: 
Does Buddhism have anything to say to such scenarios?

The precepts are in a way minimum requirements. There are lots of actions that are unwholesome, that are not specifically listed in the precepts, but that does not make them any less unwholesome.
One cannot simply say that if an action does not violate a precept, then it must be okay to do it.
One must both observe the intention (cetanā) behind the action, i.e. is it based in the 3 unwholesome roots and what kind of consequences will be the result of the action, i.e. will the action be wholesome for oneself and for other beings?
One must also strive to not only fulfill the minimum requirements but all the time see how one can improve one's mind and do as much good as one is capable off while keeping true to both oneself and other beings.
If the action is based in the 3 unwholesome roots then we already know that it cannot lead to wholesome resultants for oneself or other people. Such actions will only lead one further away from Nibbana.

Does fairness come into it?

Fairness can be implicit or derived from the precepts or from the reflection-quotes given by the Buddha, e.g. when he talks about how actions that are displeasing and disagreeable to him, how can he then inflict them upon another being?

"Again, householders, a noble disciple reflects thus: 'If some­ one were to address me with harsh speech, that would not be pleasing and agreeable to me. Now if I were to address another with harsh speech, that would not be pleasing and agreeable to the other either. What is displeasing and disagreeable to me is displeasing and disagreeable to the other too. How can I inflict upon another what is displeasing and dis­agreeable to me?"
-- Sotapatti Samyutta: Veludvareyya Sutta


user254: I'm looking at the Sallekha Sutta.

What's the rationale or logic behind the precepts? Does fairness come into it?

Maybe the rationale is 'effacement', a.k.a. removal of personal defilements.

Are the list of precepts ever expanded to accommodate changing contexts?

The Sallekha Sutta seems to do that, by including 44 items:

Starting with being harmful or harmless
Then four of the traditional precepts (killing, stealing, lying, and unchastity)
Different types of wrong speech (false, malicious, harsh, gossip)
Covetousness
Each of the eightfold way (wrong view etc.)
Various other defilements and fetters (agitation, doubt, anger, envy, arrogance, bad friends, etc.)


For example, employees of large corporations often feel lied to, even cheated when they are laid off by their employer because of new management policy. Yet, these are explicitly the terms of most employment contracts.

People lose their jobs, even permanent jobs are impermanent (in France they're not called "temporary job" and "permanent job", they're called "defined duration contract" and "indefinite duration contact").
However because that is "explicitly the terms of most employment contracts" so I'm not sure why a person should "feel lied to".
In the past I've tried to negotiate "fairness" in my own employment contract, e.g. when the contract says that the employer can end the contract by giving X amount (e.g. 2 weeks or 6 weeks) of notice, I asked that I be allowed to give the same X amount of notice for me to be allowed to end the contract.
Unrelated to Buddhism, Wikipedia's Contract article (including the related articles in the sidebar) implies that law has made an effort to promote and regulate "fairness" in contracts -- so that although some people/parties are richer than others they have (in theory) equal or equitable legal rights. 

Yet, this too is an agreed upon constraint because one party operates from a position of power.

It's asymmetrical: one bank has thousands of clients.

Modern life relies on governments, corporations and other faceless institutions to a large degree, and they do wield a great deal of power, so a lot of their transgressions fall afoul of the fairness test, though technically none of them are lies. This has to be a large source of misery in this world today. Yet, going by the precepts, at least to me, such behaviour doesn't seem to be overtly criticised. Does Buddhism have anything to say to such scenarios?

There's some advice in the Sigalovada Sutta, for example,

In five ways should workers and servants as the lower direction be
  respected by an employer: by allocating work according to aptitude,
  providing wages and food, looking after the sick, sharing special
  treats, and giving reasonable time off work.
"And, workers and servants so respected reciprocate with compassion in
  five ways: being willing to start early and finish late when
  necessary, taking only what is given, doing work well, and promoting a
  good reputation.
"In this way, the lower direction is protected and made peaceful and
  secure.

I don't know but that might have been advice for a feudal society, a society with less labour mobility (i.e. where people had fewer employers, perhaps only one).
Buddhism I suppose has been applied to lots of different societies: monarchies, feudal systems, etc.
See also How compatible are Buddhism and Communism?
IMO Buddhism isn't very responsible for the state of society or modern society. It's more responsible for (and has a lot more to say about, see e.g. the Vinaya) Buddhist monastic society: so far as I know the Buddha put more into organizing the Sangha than into organizing society-at-large. I don't know whether you consider monastic life "fair" or "unfair".

715: <ul>
<li>What's the rationale or logic behind the precepts? </li>
<li>Does fairness come into it? </li>
<li>Are the list of precepts ever expanded to accommodate changing contexts?</li>
</ul>

<p>Being very unfair to someone who trusts one is pretty similar in emotional harm to cheating on a spouse or lying, especially when the unfairness is made possible because of an abuse of a position of power. </p>

<p>For example, employees of large corporations often feel lied to, even cheated when they are laid off by their employer because of new management policy. Yet, these are explicitly the terms of most employment contracts.</p>

<p>Similarly, a home owner can feel pretty awful when evicted by the bank or lender for failure to pay the mortgage, especially when the bank is usually writing all the rules ab-initio protecting itself from market risks. Yet, this too is an agreed upon constraint because one party operates from a position of power.</p>

<p>Modern life relies on governments, corporations and other faceless institutions to a large degree, and they do wield a great deal of power, so a lot of their transgressions fall afoul of the fairness test, though technically none of them are lies. This has to be a large source of misery in this world today.</p>

<p>Yet, going by the precepts, at least to me, such behaviour doesn't seem to be overtly criticised.</p>

<p>Does Buddhism have anything to say to such scenarios?</p>
 5805: <p>"Do not be unfair" is pretty vague. Do not lie and do not steal, those are easy recognize and not do. What is fair and unfair is subject to debate, well so are perhaps all precepts but I would say unfairness even more so. </p>

<p>Who says its unfair to sack an employee? The entire system is unfair if it forces a company to sack anybody. The problem isn't with the individual, not in the scenarios you mentioned anyway. Does an economic system accumulate good and bad karma? They're not sentient so they can't follow precepts. </p>

<p>Just because a home owner feels awful doesn't mean its unfair. Don't get into the game if you don't want to play, meaning don't make loans if you might not be able to pay them. </p>

<p>I don't know what Buddhism has to say, but escaping the hassle of financial injustice does seem to be one of the perks of becoming a monk. Maybe the Buddha felt great leaving royal life behind and not having to concern himself with taxes, but this is just speculation. </p>
 -1: <blockquote>
<p>Does Buddhism have anything to say to such scenarios?</p>
</blockquote>
<p>The precepts are in a way minimum requirements. There are lots of actions that are unwholesome, that are not specifically listed in the precepts, but that does not make them any less unwholesome.</p>
<p>One cannot simply say that if an action does not violate a precept, then it must be okay to do it.</p>
<p>One must both observe the <em>intention (cetanā)</em> behind the action, i.e. is it based in the 3 unwholesome roots and what kind of consequences will be the result of the action, i.e. will the action be wholesome for oneself and for other beings?</p>
<p>One must also strive to not only fulfill the minimum requirements but all the time see how one can improve one's mind and do as much good as one is capable off while keeping true to both oneself and other beings.</p>
<p>If the action is based in the 3 unwholesome roots then we already know that it cannot lead to wholesome resultants for oneself or other people. Such actions will only lead one further away from Nibbana.</p>
<blockquote>
<p>Does fairness come into it?</p>
</blockquote>
<p>Fairness can be implicit or derived from the precepts or from the reflection-quotes given by the Buddha, e.g. when he talks about how actions that are displeasing and disagreeable to him, how can he then inflict them upon another being?</p>
<blockquote>
<p>&quot;Again, householders, a noble disciple reflects thus: 'If some­ one were to address me with harsh speech, that would not be pleasing and agreeable to me. Now if I were to address another with harsh speech, that would not be pleasing and agreeable to the other either. What is displeasing and disagreeable to me is displeasing and disagreeable to the other too. How can I inflict upon another what is displeasing and dis­agreeable to me?&quot;</p>
<p>-- <em>Sotapatti Samyutta: Veludvareyya Sutta</em></p>
</blockquote>
 254: <p>I'm looking at the <a href="http://www.accesstoinsight.org/tipitaka/mn/mn.008.nypo.html" rel="nofollow noreferrer">Sallekha Sutta</a>.</p>

<blockquote>
  <p><em>What's the rationale or logic behind the precepts? Does fairness come into it?</em></p>
</blockquote>

<p>Maybe the rationale is 'effacement', a.k.a. removal of personal defilements.</p>

<blockquote>
  <p><em>Are the list of precepts ever expanded to accommodate changing contexts?</em></p>
</blockquote>

<p>The Sallekha Sutta seems to do that, by including 44 items:</p>

<ul>
<li>Starting with being harmful or harmless</li>
<li>Then four of the traditional precepts (killing, stealing, lying, and unchastity)</li>
<li>Different types of wrong speech (false, malicious, harsh, gossip)</li>
<li>Covetousness</li>
<li>Each of the eightfold way (wrong view etc.)</li>
<li>Various other defilements and fetters (agitation, doubt, anger, envy, arrogance, bad friends, etc.)</li>
</ul>

<blockquote>
  <p><em>For example, employees of large corporations often feel lied to, even cheated when they are laid off by their employer because of new management policy. Yet, these are explicitly the terms of most employment contracts.</em></p>
</blockquote>

<p>People lose their jobs, even permanent jobs are impermanent (in France they're not called "temporary job" and "permanent job", they're called "defined duration contract" and "indefinite duration contact").</p>

<p>However because that is "explicitly the terms of most employment contracts" so I'm not sure why a person should "feel lied to".</p>

<p>In the past I've tried to negotiate "fairness" in my own employment contract, e.g. when the contract says that the employer can end the contract by giving X amount (e.g. 2 weeks or 6 weeks) of notice, I asked that I be allowed to give the same X amount of notice for me to be allowed to end the contract.</p>

<p>Unrelated to Buddhism, Wikipedia's <a href="https://en.wikipedia.org/wiki/Contract" rel="nofollow noreferrer">Contract</a> article (including the related articles in the sidebar) implies that law has made an effort to promote and regulate "fairness" in contracts -- so that although some people/parties are richer than others they have (in theory) equal or equitable legal rights. </p>

<blockquote>
  <p><em>Yet, this too is an agreed upon constraint because one party operates from a position of power.</em></p>
</blockquote>

<p>It's asymmetrical: one bank has thousands of clients.</p>

<blockquote>
  <p><em>Modern life relies on governments, corporations and other faceless institutions to a large degree, and they do wield a great deal of power, so a lot of their transgressions fall afoul of the fairness test, though technically none of them are lies. This has to be a large source of misery in this world today. Yet, going by the precepts, at least to me, such behaviour doesn't seem to be overtly criticised. Does Buddhism have anything to say to such scenarios?</em></p>
</blockquote>

<p>There's some advice in the <a href="http://www.accesstoinsight.org/tipitaka/dn/dn.31.0.ksw0.html" rel="nofollow noreferrer">Sigalovada Sutta</a>, for example,</p>

<blockquote>
  <p>In five ways should workers and servants as the lower direction be
  respected by an employer: by allocating work according to aptitude,
  providing wages and food, looking after the sick, sharing special
  treats, and giving reasonable time off work.</p>
  
  <p>"And, workers and servants so respected reciprocate with compassion in
  five ways: being willing to start early and finish late when
  necessary, taking only what is given, doing work well, and promoting a
  good reputation.</p>
  
  <p>"In this way, the lower direction is protected and made peaceful and
  secure.</p>
</blockquote>

<p>I don't know but that might have been advice for a feudal society, a society with less labour mobility (i.e. where people had fewer employers, perhaps only one).</p>

<p>Buddhism I suppose has been applied to lots of different societies: monarchies, feudal systems, etc.</p>

<p>See also <a href="https://buddhism.stackexchange.com/q/1529/254">How compatible are Buddhism and Communism?</a></p>

<p>IMO Buddhism isn't very responsible for the state of society or modern society. It's more responsible for (and has a lot more to say about, see e.g. the Vinaya) Buddhist monastic society: so far as I know the Buddha put more into organizing the Sangha than into organizing society-at-large. I don't know whether you consider monastic life "fair" or "unfair".</p>
