A growing empirical literature uses patent citations as a quality-adjusted measure for innovation, despite concerns about the validity of this measure. This paper links patents with objective measures of improvements in the quality of patented inventions – measured through performance in field...

A growing empirical literature uses patent citations as a quality-adjusted measure for innovation, despite concerns about the validity of this measure. This paper links patents with objective measures of improvements in the quality of patented inventions – measured through performance in field...

Starting in the 1930s, commercial hybrid corn seeds rapidly replaced the once predominant open-pollinated varieties planted by farmers. By the mid-1950s almost all corn grown in the United States was of hybrid varieties. Observers have argued that the drought tolerant qualities of these hybrids...

Starting in the 1930s, commercial hybrid corn seeds rapidly replaced the once predominant open-pollinated varieties planted by farmers. By the mid-1950s almost all corn grown in the United States was of hybrid varieties. Observers have argued that the drought tolerant qualities of these hybrids...