Would you work on a starship that won't be completed for a hundred years?

Is economic growth inexorably slowing down?

That was the question in my mind when reading this good post by John Cochrane.

For the right money I might, but that begs the question, would you invest in a project that won't be completed for a hundred years? Would you vote for a government project that wouldn't be completed for a hundred years?

Here is a related question.  How hard would you look for a task that will be completed in a few years?  What if all the best projects require require a hundred years?

My point being that depreciation cycles get longer as the value chains grow longer.  Economies of scale, value chain length and productivity are mostly the same concept.  

Why are people staring at their smart phone screens? Because the real life transactions are too fast in the urban dense economies with increasing economies of scale.  We have a limit, our cities have Avogadro numbers. If we want to go higher, we need extra dimensionality, and we do not have it.  More importantly, human comfort is exceeded when we cannot stop to say hello, and we will exit the task due to discomfort.

This problem needs solutions, generally in the form of real artificial intelligence, the kind outlawed by the NSA. Allow us to have an autonomous contract manager in our smart phones and we will be staring at our screen much less, and saying hello more often. But the screens are still useful, when we need them the information displayed will be much more accurate and complete. A good balance for big tech, our welfare bums of the day.