Lying, on a jet plane
The jet-plane's-haven't-improved idea is even more ridiculous that Tim makes clear. To quote a commenter I saw recently on another site:
"There have been and continue to be large and impressive improvements in their: reliability, fuel efficiency, NOx emissions, CO2 emissions, noise levels, soot & smoke emissions, weight reduction and thrust rating (especially in proportion to weight). The latest Jet powered Aircraft are getting 2.4 to 2.5 Liters/passenger/100km fuel efficiency! The previous generation was around 4.5 to 6.5 and in the 70's it was around 10L/Pass/100Km! The Concorde was 16.6L/Pass/100Km!"
Other than that, given this is a tech site, I think it's worth looking at the costs of the computer revolution. It's basic common-sense that we expect the widespread adoption of new technologies to reduce growth in the shorter term - when consumers do it, we talk about the early-adoption penalty. Arguably, we've been putting resources into building up to a level where we can really exploit IT.
Commensurately, it has been argued that the roots of the previous boom were in the industrial revolution, and what we saw in the boom was the opportunity for rapid exploitation that eventually resulted from all the effort put in earlier.