Jeff Ralph is a visiting academic at the University of Southampton, UK. He worked for the Office for National Statistics, UK, for 14 years, retiring in 2018. Much of that time was spent working on price statistics and the measurement of inflation; this included research and teaching. He has been joint author on a number of research papers and co-author of books on index numbers and inflation measurement. Robert O’Neill is Lecturer in Economics at the University of Manchester, UK, where he has been since the start of 2020. Previously he was Senior Lecturer in Economics at Huddersfield University, UK and before that he worked at the Office for National Statistics. His current role involves both research and teaching related to quantitative economics, which includes teaching students at various levels. Paul A. Smith is Professor of Official Statistics at the University of Southampton, UK. He previously worked for 25 years at the Office for NationalStatistics, UK, where he gained extensive experience in the theory and practice of sample surveys applied to businesses, households and the population census. He undertakes consultancy and research in topics related to official statistics, and coordinates the MSc in Official Statistics.