Without question, if we replace the word "progress" with the word "production" in our inclining arc to the left or front side of Hubbert's curve, there might be very few who would disagree with that notion? So, instead of "arc of progress" we'll try on "arc of production" for size, just now? So we have an inclining "arc of production", that comes to a peak and then after, a declining arc of production, when the resource base cannot support it. As Detroit's industrial production grew, so did the population. When much of the resource base left the city, causing it to decline in production and was used at near by suburban areas, much of the population followed it. This process can be seen in many of our Nation's cities and towns, today. This process lead to what many call the "doughnut hole" effect, causing the the inner city to lose population while surrounding areas or suburbs, gained it.
If the resource base is declining, making further gains in production impossible, then perhaps making things such as houses smaller and more efficient, using less resource, only makes sense in the future? Is it possible that Detroit could return to it's former glory of being the center of industrial activity in this country again? I don't know but think, if it does it'll likely be much smaller in size comparable to the the home at the bottom than the one at the top. It would take considerably less resource to maintain the smaller house. One thing is certain, if Detroit is going to have any substantial recovery at all, much of the resource base must return to it, causing production to rise, so the people can return to it.