From Dan Ferris in the S&A Digest:

The streets of Mumbai, India, are so congested, you can't walk on them. So the city is going to spend $300 million to build 50 elevated steel walkways to allow pedestrians to get where they're going. Mumbai has nearly 18 million people and its sidewalks are crowded with street vendors, some of whom have been selling their wares on the same spot for 20 years or more, according to the Wall Street Journal.

I hear the word "infrastructure" thrown around a lot, especially when investors talk about China and India. But I rarely hear anyone tell me what it really means in simple terms that anyone can understand.

A city of 18 million without enough sidewalk space... that I understand.

Mumbai's space problem reminds me of Julian Simon, economist and author of The Ultimate Resource II. The ultimate resource Simon refers to is human beings. Peak Oil proponents and other environmental alarmists don't get that with every new mouth to feed comes a new brain that thinks. Though there can certainly be short-term shortages of various goods and services - like walking space - over the long term, the rule for humanity has been abundance.

Think about New York City. Today's population (19 million) is roughly similar to Mumbai's. But 150 years ago, the population of pre-Civil War New York wasn't near its current size, and the city would be hardly recognizable compared with today's metro area.

Given Mumbai is starting off with enormous population resources, imagine what 150 years of progress will look like there. New York to the 10th power? It boggles the mind.

This potential for huge growth excites investors more than just about anything else. It's the reason Jim Rogers remains so bullish on China, despite his admission that property markets there are overheated. I'm heading over to Chennai, India, in early March. Maybe I'll have a good sidewalk story to tell when I get back.

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