More items of note on agglomeration:

From City Journal, the “Seven Pillars of Agglomeration.”

1. Economies of scale in production
2. Economies of scale in trade and transportation
3. Falling transportation and communication costs
4. Proximity with other firms in the same industry
5. Advantages of diversity
6. The quest for the center (of the industry)
7. Buzz and bright lights

And, from The New Republic‘s Avenue blog, a visualization of those principles in action, looking at the athletic and outerwear industry in Portland, OR – from Pendleton (1889) to Nike (1978).

But the A&O cluster is also an interesting case study in cluster morphology and dynamics. Check out this cool genealogy map developed by sometime Metro Program author Heike Mayer of the University of Bern, for example. Meyer’s info-graphic shows well how the A&O cluster has grown over time and now epitomizes the frequent structure of highly dynamic clusters, which often find a small number of large foundation firms (in this case Nike, Adidas, and Columbia Sportswear) surrounded by a cloud of scores of smaller, more entrepreneurial firms. In Portland, hundreds of these small and sometimes tiny firms are now proliferating–driving growth, developing their own niches, and providing services to the bigs and larger new firms.

The accompanying infographic (full size image – PDF file) shows this phenomenon in action, and through time.  As noted, building on these existing clusters, taking advantage of these agglomerations is the smart approach to economic development:

All together, it’s a great example of how the best sort of economic development eschews chasing after firm relocations and other silver bullets and instead concentrates on “organic” growth that arises from local distinctiveness.

Agglomeration is about letting cities be cities.