"Wage Policy in the Health Care Sector: A Panel Data Analysis of Nurses' Labour Supply," with Jan Erik Askildsen and Tor Helge Holmas, Health Economics, Vol 12 (September, 2003), pp. 705-719.

"Skilled-Biased Technical Change in U.S. Manufacturing: A General Index Approach," with Daniel Rich, Journal of Econometrics, Vol. 126 (June, 2005), pp. 549-570.

"A Panel Data Study of Physician's Labor Supply: The Case of Norway," with Espen Bratberg and Tor Helge Holmas, Health Economics, Vol. 14 (October, 2005), pp. 1035-1045.

"Estimating An Economic Model of Crime Using Panel Data from North Carolina," Journal of Applied Econometrics, Vol. 21 (May-June, 2006), pp. 543-547.

"Rational Alcohol Addiction: Evidence from the Russian Longitudinal Monitoring Survey," with Ingo Geishecker, Health Economics, Vol. 15 (September, 2006), pp. 893-914.

"Random Effects and Spatial Autocorrelation with Equal Weights," Econometric Theory, Vol. 22 (October, 2006), pp.973-984.

"Joint LM Test for Heteroskedasticity in a One-Way Error Component Model," with George Bresson and Alain Pirotte, Journal of Econometrics, Vol. 134 (October, 2006), pp. 401-417.

"Panel Unit Root Tests and Spatial Dependence," with George Bresson and Alain Pirotte, Journal of Applied Econometrics, Vol. 22 (March, 2007), pp. 339-360.

"Testing for Serial Correlation, Spatial Autocorrelation and Random Effects Using Panel Data," with Seuck Heun Song, Byoung Cheol Jung and Won Koh, Journal of Econometrics, Vol. 140 (September, 2007), pp. 5-51.

"Estimating Models of Complex FDI: Are There Third Country Effects?," with Peter Egger and Michael Pfaffermayr, Journal of Econometrics, Vol. 140 (September, 2007), pp. 260-281.

"Worldwide Econometrics Rankings: 1989-2005," Econometric Theory, Vol. 23 (October, 2007), pp. 952-1012.