Being able to meaningfully disagree is something I treasure in friends. I've found this discussion about the correct way to disagree to be informative: http://commonsenseatheism.com/?p=13435

Everything matters

Communication is a holistic phenomena. When you listen to speech, you consider the motives, interests, and abilities of the speaker in pursuing the resulting goals. You ask yourself why someone is saying something the way that they are saying it.

Are you saying I'm stupid?

This is one of those things that trips me up every so often, especially in one-to-one conversations. When we are in a group, it's easy to understand that disagreement can be seen as an affront; conversely, it can be difficult to remember that people take badly to disagreement in private conversation as well.

Is it interesting to you too?

Topics inevitably drift over the course of a conversation, and picking up cues and allowing the topic to change in the right direction is also important, lest what one considers a profound line of thought is taken by the other to be irrelevant inanity. I imagine religious aphorisms to be a stark example of this - I believe there are people out there for whom the ability to conclude a conversation to a biblical quotation or some other aphorism is profound, whereas such is somewhat inane to me.

Classic prose

Addressing all these facets can be done by adopting the style of classic prose. Classic prose is a simplifying construct which manages to compartmentalize conversational causes and to clarify what would otherwise be an even more impressionistic exercise. It's a construct that prioritizes simplicity and clarity over all else.

http://classicprose.com/csx.html:

The role is severely limited because classic prose is pure, fearless, cool, and relentless. It asks no quarter and gives no quarter to anyone, including the writer. While the role can be necessary, true, and useful, as well as wonderfully thrilling, it can hardly be permanent. For better or worse, human beings are not pure, fearless, cool, or relentless, even if we may find it convenient for certain purposes to pretend that we are. The human condition does not, in general, allow the degree of autonomy and certainty that the classic writer pretends to have. It does not sustain the classic writer's claim to disinterested expression of unconditional truth. It does not allow the writer indefinitely to maintain the posture required by classic style. But classic style simply does not acknowledge the human condition. The insouciance required to ignore what everyone knows and to carry the reader along in this style cannot be maintained very long, and the masters of the style always know its limits. The classic distance is a sprint.

 

What if your tax rate was lower?
Well, I would probably get more post-tax income.

For every dollar less of taxes, would you get one dollar of additional post-tax income?
No, because I might get a lower salary.

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What if the government dictated that rent in my area was not to increase more than 1% a year?
My rent would probably be cheaper than rent in other areas.

Isn't that great?
Well, not if the house falls into disrepair because the landlord find it not worthwhile to maintain the property after a few years.

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What if the government raised taxes on companies?
Companies will pay more taxes.

Isn't this a good thing?
Well, things might get pricier too, as those new costs are passed on.

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Cross-elasticity is a very broad phenomena. Any profit-generating activity that involves multiple inputs and outputs has many ways of adjusting those inputs and outputs to maximize value (be it profit or consumption), and when prices are changed for one input or output it will affect the demand / supply of the other inputs and outputs in some way that can be difficult to anticipate.

To assume that the only change would be in the adjusted input / output is naive.

Related video: http://www.youtube.com/watch?v=9b-w7GOTqSY