The Penn World Table (PWT) is a set of national-accounts data developed to measure real GDP across 167 countries over time (1950-2014) and data on prices, capital, productivity, employment and population.
Developed and maintained by scholars at the University of California, Davis and the Groningen Growth Development Centre of the University of Groningen. The database gets it name from the original developers at the University of Pennsylvania. Penn World Table version 8.0 available from http://cid.econ.ucdavis.edu/pwt.html.