We compare estimates of the effects of education on health and health behaviour using two different instrumental variables in the UK Biobank data. One is based on a conventional natural experiment while the other, known as Mendelian randomization (MR), is based on genetic variants. The natural...

We investigate the behaviour of the Lasso for selecting invalid instruments in linear instrumental variables models for estimating causal effects of exposures on outcomes, as proposed recently by Kang, Zhang, Cai and Small (2016, Journal of the American Statistical Association). Invalid...