[wpietri]

The paper says "We estimate that between 1992 and 2016, real price per energy capacity declined 13% per year". Where do you get your data for the last 5 years?

Regardless, 1 year isn't the correct duration for a bet. People average owning a car for ~6 years, and the average lifespan is something like 12 years.

But depending on terms, I might take a year-over-year bet for battery prices. Demand is high and the pandemic has caused significant supply chain problems. They could well have gone up this year. And indeed, a quick look at news reports suggests key components, including lithium and cobalt, are surging in price. Fine examples of why assuming a historical average has future meaning can get you into trouble.

[Tade0]

One kWh of batteries generally requires around 200g of lithium. Both by weight and price it's a crucial, but small component, so unless it suffered a 10x hike, its price isn't relevant.

Meanwhile LiFePO4 batteries, which are currently the most popular chemistry(at least in China), contain no cobalt whatsoever.

[wpietri]

Other analysts differ on whether these things will impact the retail price. But you make my point for me: this is an extremely complex problem, and making any simple assumption about future price is a mistake.

[AtlasBarfed]

Or Nickel, the other limiting factor to top-end batteries.

[Brakenshire]

BNEF do a price survey, prices have continued to decline at the same rate. The decline was exactly 13% again last year.

Lithium prices have gone down in the last few years, and Cobalt isn’t a necessary component.