Mario Polèse has a piece about Why Big Cities matter More than Ever in, appropriately enough, City Journal.
He makes many worthwhile points. My favourite one (i.e. I already strongly agree) is that the rise of electronic communication at a distance intensifies (rather than reduces) the demand for face-to-face contact, and hence for transport. Not all information can be transmitted over wires or through the ether. That much can increases the value of face-to-face meetings (like this one for instance), because quality face-to-face teams can now influence and trade with the entire world.
What about the argument that falling communications costs actually undermine urban concentration? For example, didn’t the existence of e-mail encourage Silicon Valley companies to outsource computer programming to Bangalore, India? The truth is that this shift did foster urban concentration - in Bangalore.
As for falling physical transport costs causing physical dispersion, well, yes and no. Consider the live theatre business. Theatrical endeavour clusters in one spot (like Broadway or the West End of London), for all the usual reasons that businesses cluster (economies of scale - big pools of core professional talent - variety of ancillary professional talent - inside info - face-to-face contact (see above)), but good transport enables more punters to come to town, to witness these performances. Transport enables a dispersed population all to benefit from the same services, which it thus makes more sense to be concentrated in the big city.
Transport, in other words, isn’t going anywhere.