I'm not sure you can compare an existing factory in China with a non-existing factory in upstate New York. The two have very different environments to contend with. In China, they already have supply chains, investors, and customers. Whereas an non-existent or proposed factory has to set each of these up and still contend with competition with the existing factories. The only real advantage a factory that's local (like one in upstate New York) is they'll be closest to the demand for that region. So, they can attenuate their output when demand rises/lowers. But as a whole this is only a potential benefit in terms of the ecological impact (reduced over production for some products). And I say potential because some areas are better manufacturing certain products like it's cheaper to extract aluminium British Columbia where they have cheap power due to hydroelectric power than say S. America where you find the aluminium ore rich soils. Getting around infrastructure limitations won't be as easy as simply pouring more concrete. Some places just will never be able to compete and I think this is something some folks need to address in such articles.