probably helps because it was, created in clusters, many times, as part of the industrial revolution. Pretty easy to cure something if it happens so often. ht

probably helps because it was, created in clusters, many times, as part of the industrial revolution. Pretty easy to cure something if it happens so often. https://academic.oup.com/aje/article-abstract/162/9/817/58326?redirectedFrom=fulltext https://academic.oup.com/aje/article-abstract/162/9/817/5832...