How Important is Technology Capital for the United States?
测算了1982-2007年美国及全球的技术资本和开放度，发现技术资本约为有形资本的三分之一，完全封闭美国经济的福利损失很小，但完全开放的福利收益很大。
I construct measures of technology capital and country openness for the US economy and the rest of the world for 1982–2007. The key identifying assumption is that firms equalize returns on tangible and technology capital. For the US economy, technology capital is about one-third of tangible capital, and the degree of openness is between 0.61 and 0.70. I provide both a two-country estimation and a multicountry estimation, and find that the US estimates are almost identical in both cases. The welfare loss from totally closing the US economy is small, but the welfare gain from totally opening the US economy is large.