Influential research by Professor Yongcheol Shin

The 2003 paper 'Testing for unit roots in heterogeneous panels' has become the most highly cited Journal of Econometrics paper of its decade and is celebrated in a special Jubilee issue.

Yongcheol and his co-authors' work provides a means for researchers to identify differing degrees of persistence in time series data and thereby to avoid pitfalls when data feature the kind of trends that are very common in macroeconomics and finance. It has been highly influential, both with academic and professional economists given the importance of sound time series analysis for business decisions. The product of their research (known as the IPS test) and its extensions are now included in all of the leading statistical software packages and major textbooks.

These articles are followed by the author(s) retrospective on their papers. 

The most cited paper in each decade, based on Google scholar citation counts in October 2022, are: 

1. Aigner, Lovell and Schmidt (1997): Formulation and estimation of stochastic frontier production function models (14,236 citations) 
2. Bollerslev (1986): Generalized autoregressive conditional heteroskedasticity (31,142 citations) 
3. Blundell and Bond (1998): Initial conditions and moment restrictions in dynamic panel data models (24,870 citations) 
4. Im, Pesaran and Shin (2003): Testing for unit roots in heterogeneous panels (15,749 citations) 
5. Diebold and Yilmaz (2014): On the network topology of variance decompositions: Measuring the connectedness of financial firms (1,763 citations) 

These five papers are reprinted in this issue along with reflections from the authors. Ours is Reflections on “Testing for Unit Roots in Heterogeneous Panels.”