Passage of the day

"The city's economy is made up of strange, subterranean circuits that are as mysterious to you as the grids of wire and pipe under the streets"
Jay McInnery, 'Bright Lights, Big City', p.86'

It's in the context of how fast umbrella-sellers spring up as soon as it starts to rain. The protagonist is wondering what mechanism mobilises them all so quickly. He's not familiar with Hayek, nor Kirzner clearly.