[dan-robertson]

This seems like a pretty bad reason to want speed limits, because the thing you actually want to limit is fuel inefficiency. I think rules should normally try to achieve their goals through first-order effects rather than second order effects.

I don’t think wanting fuel efficiency is incompatible with getting rid of the speed limit rule.

[idiotsecant]

Sometimes behaviour is legislated through second order behaviours because legislating first order behaviour is politically sensitive, or sometimes because even though the primary behaviour is already legislated the second order behaviour is as well. Not saying it's right, but it's exceedingly common.

I'd make an example but these are exactly the sort of things that launch off topic 10 page discussions with very low information content.

[dan-robertson]

Sure, there are exceptions. When I wrote ‘normally’ to cover them, I was more thinking of things where it is hard to set good metrics for the thing one wants controlled, or cases where avoiding the spirit of the rule would be too likely.

Nevertheless, I think those are exceptions. I think first order effects tend to matter more than second order effects (that’s why they’re called first order) and not doing good first-order things because of potentially bad second-order things is often wrong.

[slowmovintarget]

And sometimes the legislation is the way it is because the legislature works from an understanding that is easy to popularize... and wrong.

[sokoloff]

I agree with you and, in this case, taxing Jet-A seems like an incredibly straightforward way to accomplish this.

[buck4roo]

That sound you hear from aircraft overhead -- yeah, that's wasted energy.

Do you want waste? Because that's how you get waste!

[mgbmtl]

I would be a bit skeptical, considering how many car makers tried to trick the measurement of emissions. Create a metric, people will game it.

[dan-robertson]

Cars are regulated pretty differently from air travel though? And airlines are already quite incentivised to use less fuel as it’s a huge cost. I think it’s just a case of different things being different.

[itake]

Even perfect fuel efficiency, higher speeds will require more energy than lower speeds.

More energy will cost more fossil fuels.

[dan-robertson]

Doesn’t nearly-supersonic flight require more fuel than supersonic flight, at least in some cases? That seems to contradict fuel efficiency being a decreasing function of speed.