Astrid Cullmann is senior researcher in the Department Energy, Transportation, and Environment. Her research deals with productivity and regulation of public sector firms. She focuses on municipal state-owned firms in the energy and water sector. Astrid is also Senior Lecturer at the Chair of Econometrics and Business Statistics at TU Berlin. She studied Economics at Free University Berlin and University Carlos III in Madrid. She obtained her PhD in economics in 2009 from TU Berlin.