TY  - JOUR
AU  - Griffith,Rachel
AU  - Lee,Sokbae
AU  - Reenen,John Van
TI  - Is Distance Dying at Last? Falling Home Bias in Fixed Effects Models of Patent Citations
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 13338
PY  - 2007
Y2  - August 2007
UR  - http://www.nber.org/papers/w13338
L1  - http://www.nber.org/papers/w13338.pdf
N1  - Author contact info:
Rachel Griffith
IFS
7 Ridgmont Street
London WC1E 7AE
UK
E-Mail: rgriffith@ifs.org.uk

Sokbae Lee
University College London
Gower Street
London WC1E 6BT
United Kingdom
E-Mail: l.simon@ucl.ac.uk

John Van Reenen
Department of Economics
London School of Economics
Centre for Economic Performance
Houghton Street
London WC2A 2AE
UNITED KINGDOM
Tel: 00 44 207/955-6976
Fax: 00 44 207/955-6848
E-Mail: j.vanreenen@lse.ac.uk
AB  - We examine the home bias of international knowledge spillovers as measured by the speed of patent citations (i.e. knowledge spreads slowly over international boundaries). We present the first compelling econometric evidence that the geographical localization of knowledge spillovers has fallen over time, as we would expect from the dramatic fall in communication and travel costs. Our proposed estimator controls for correlated fixed effects and censoring in duration models and we apply it to data on over two million citations between 1975 and 1999. Home bias declines substantially when we control for fixed effects: there is practically no home bias for the more modern sectors such as pharmaceuticals and information/communication technologies.
ER  -