Gates wrote a Linkedin post earlier this month about "Capitalism Without Capital," which was written by two economists.
The book examines one of the most important modern shifts in the global economy: companies and governments are investing in "intangible assets" — things like software and research.
"This is one of the biggest trends in the global economy that isn't getting enough attention," Gates wrote.
These intangible assets are produced differently than regular assets like cars and machinery. As Gates explains:
"Microsoft might spend a lot of money to develop the first unit of a new program, but every unit after that is virtually free to produce. Unlike the goods that powered our economy in the past, software is an intangible asset. And software isn't the only example: data, insurance, e-books, even movies work in similar ways."
According to Gates, this trend has huge ramifications for the global economy. For example, GDP calculations don't account for spending on branding and market research, yet many major companies are centered around those intangible assets.
"What is the best way to stimulate an economy in a world where capitalism happens without capital gains?" Gates said. "We need really smart thinkers and brilliant economists digging into all of these questions."