Charlotte, that’s the right question to ask. But it’s surely complicated to answer. Here is a partial attempt.
The ‘elasticity of demand’ for transportation is estimated to be about 0.7 in the long term, which means that if prices drop 10X, demand will increase 7X. That’s an estimate, of course, but it’s what we have now, so let’s go with it.
As I wrote in my piece on Big Oil and it’s follow-on, self-driving vehicles make the most economic sense when they are electric. I can also make the assumption that the EVs are powered by renewables, since that is about to become the cheapest source of electricity in most locations of the world. (Really.) The energy efficiency of an EV will then be about 3–4X that of an internal combustion vehicle, since an internal combustion engine is a pretty inefficient way to power anything. Let’s call that 3.5X more efficient; therefore, we will need 2X more energy dedicated to transport in this future world.
That is not chump change — doubling the amount of energy spent on transport would on its own send the planet into a Venus-style greenhouse effect. It also means 7X the traffic. But the vehicles will be silent, with nothing but tire noise. Congestion would not necessarily increase, since most of the delivery traffic will be outside rush hour (you can’t deliver to a traveling person). Bobots don’t rubberneck and theoretically should get into far fewer accidents. And this transition is not instantaneous — the short term elasticity of demand for transportation is just 0.3, which means that in the short run there will be no energy penalty at all relative to today.
And over the long term, on-demand delivery allows us to live in smaller places and consume fewer things. Less food will spoil. Less plastic junk will be returned to the earth as trash. And who knows what other technology will intersect with this one in a decade, creating possibilities that don’t exist today.
My bottom line here is that I can see a lot of upside, and I think the downside is manageable. I can’t rigorously prove that last statement, but I am not seeing this technology blow the world up, and I am seeing it make the world more efficient. Maybe I’m just an optimist, but I think there is cause for hope for both a better, richer future and a better planet.