  Communication technologies, from printing to social media, affect our
historical records by changing the way ideas are spread and recorded. Yet,
finding statistical instruments to address the endogeneity of this relationship
has been problematic. Here we use a city's distance to Mainz as an instrument
for the introduction of the printing press in European cities, together with
data on nearly 50 thousand biographies, to show that cities that adopted
printing earlier were more likely to be the birthplace of a famous scientist or
artist in the years after the introduction of printing. At the global scale, we
find that the introduction of printing is associated with a significant and
discontinuous increase in the number of biographies available from people born
after the introduction of printing. We bring these findings to more recent
communication technologies by showing that the number of radios and televisions
in a country correlates with the number of performing artists and sports
players from that country that reached global fame, even after controlling for
GDP, population, and including country and year fixed effects. These findings
support the hypothesis that the introduction of communication technologies
shift historical records in the direction of the content that is best suited
for each technology.
