@unpublished{Aghion2002,
author = {Philippe Aghion and Nicholas Bloom and Richard Blundell and Rachel Griffith and Peter Howitt},
title = {Competition and innovation: an inverted U relationship},
year = {2002},
month = {Feb},
volume = {pp},
doi = {10.1920/wp.ifs.2002.0204},
issn = {1742-0415},
url = {http://www.ifs.org.uk/wps/wp0204.pdf},
}