Vlad Achimescu is working as a teaching and research assistant at the Professorship for Statistics and Methodology at the University of Mannheim. He is currently interested in assessing data quality in probabilistic and non-probabilistic web panels, studying the effects of panel conditioning on response times, and analysing household clustering patterns revealed by paradata. He holds a Bachelor and Master’s degree in sociology from the University of Bucharest, and also a Master’s degree in statistics from KU Leuven obtained in 2014. He wrote his master’s thesis on the topic of concentrated social exclusion in rural areas, analyzed in a multilevel model containing survey and administrative data. Before coming to Mannheim, he worked as a quantitative researcher, collaborating with several public, private and third sector research institutions in Romania. His work experience includes designing and overseeing the implementation of several nationally and regionally representative surveys using different modes of data collection, on topics ranging from labour market inclusion to education and political culture.