Depending on how you look at "improvement", that's not strictly true. Often, large data sources are slightly biased relative to the population we want to genera

Depending on how you look at "improvement", that's not strictly true. Often, large data sources are slightly biased relative to the population we want to generalize to (say, a single regional company's customers, trying to generalize to a national population). Working with larger and larger such data sets, that bias can become large relative to standard errors/credible interval width. Xiao-Li Meng has had some interesting talks/papers about this and related ideas: https://dash.harvard.edu/handle/1/10886849 https://dash.harvard.edu/handle/1/10886849