WordPress added various functions over the summer, and I'm testing the ability to embed graphs here. Why cobalt prices? Cobalt is a critical part of electric vehicle batteries, as cathodes rely upon nickel-chrome oxide crystals of various compositions (eg, along with manganese). It is a potential game-stopper, because enough is used that chrome content affects the overall price of a car. There are other chemistries ... in the lab. However, the path from lab to cost-effective volume production is at a minimum 20 years, and then adding capacity to meet the potential size of the market can (in the automotive case) take an additional two decades.
Now this isn't macroeconomics, but it is certainly a good exemplar of the challenges of turning exciting technologies into commercial realities. That IS of macroeconomic significance. Indeed, in the US context productivity is potentially the single most important contributor to economic growth over the 40-plus years your working life.
This however is a statement that needs both a theoretical foundation – what underlies growth? – and am empirical foundation – what are the numbers in the US context, and can we usefully project them for the next 4 decades? Making predictions is challenging, the moreso if they are about the distant future. Be skeptical about claims that pin that down to a precise number; be thoughtful about whether we can put likely bounds on what will happen, e.g., can we achieve 3% growth?
If I understand correctly, both these graphs should update automatically – come back in a month to see whether they still reflects Aug 26th data, which for cobalt happened to be the then historic peak of $60,750 per (metric) ton.