What Ancient Mexico Teaches Us About Urban Density

Like many Indian cities, Mexico is battling pollution, too. In May this year, the country banned 40 per cent of the vehicles on the roads to curb air pollution. Though the challenges Mexico faces are not too unlike the challenges faced by Indian cities, but, Mexico has done well in handling these challenges.

With Indian Prime Minister Narendra Modi visiting Mexico today, there is a growing recognition that Indian cities should be equipped to handle urbanisation. Now, it would be interesting to look at how similar ancient Mexico was to modern day cities. A recent study, performed by researcher Scott G. Ortman in collaboration with three other researchers, on 4,000 pre-Hispanic settlements in Ancient Mexico suggests that dense urban settlements were far more productive, even in those times.

The problems modern Mexican cities face are not unique. When cities become larger, when more people live close together in cities, there are massive gains in productivity. Buildings become taller and larger. Even though modern cities are less polluted, urban density has its downsides, too. Vehicular pollution is one of those downsides, and the spreading of contagious diseases is another. But economic progress and technological advancement tend to contain these problems to such a large degree than even when density rises, people become healthier, and vehicular pollution tends to decline.

But studies on ancient Mexico suggest that dense cities were always more productive. Even centuries ago, the total produce of dense areas in Mexico was higher than it would have been if people were isolated. For example, the GDP was higher than it would have been if people were dispersed over large areas. In other words, modern cities are not much different, fundamentally. It is simply not true that density reaps dividends only in modern capitalistic democracies.

The implication is that the world is urbanising faster than ever because we realise that productivity would be much higher if we live next to each other. Perhaps, it happens much faster today because cities have learned to deal with the costs of high density. As we have minimised the costs, it makes sense for far more people to move to urban areas. Urbanisation is a creator in cities where we have brought down the costs to bare minimum.

For example, if proximity is greater, we need not spend much of our time searching for food, clothes, medical care or other amenities. This allows people to pursue their other goals more easily, like engaging in productive activities. When people do not spend much of their time meeting their fundamental needs, they are free to acquire specialised knowledge, and to co-ordinate groups to achieve common goals.

Researchers who studied ancient Mexico looked at the size of buildings and monuments, and found that larger monuments were built in dense, urban areas. This is because such regions were more productive. Even in modern Mexico, this is true, because more people can share buses in the heart of the city. More people can share roads. To make this clear, imagine how many people share the road network in Delhi's central business district Connaught Place, as opposed to the number of people who would share a similar road in a remote village. Such economies of scale were in operation even in ancient Mexico.

Moreover, cities have markets where people can easily buy food when this is more difficult in sparsely populated areas. When obtaining food is difficult, people are forced to spend more energy in obtaining it. To see how Indian cities should develop, we should see why cities have always been places where human creativity was unleashed.