A paltry 26 per cent of psychologists were willing to send their data to other researchers upon an email request

From Science Fictions by Stuart Ritchie.  Page 130.  

The great thing about statcheck, the GRIM test, and Carlisle’s method is that they can all be performed using just the summary data that are routinely provided in papers: things like p-values, means, sample sizes and standard deviations. No access to the full, original data spreadsheets is required. That’s just as well, because scientists are notorious for their reluctance to share their data, even when other bona fide researchers ask them nicely. A study in 2006 found that a paltry 26 per cent of psychologists were willing to send their data to other researchers upon an email request, and similarly dismal figures come from other fields. You’re also much less likely to be able to access the data the older a study gets.  This reluctance to share data is a block on the vital processes of self-scrutiny – those Mertonian norms of communalism and organised scepticism again – that lie at the heart of science. And as clever as the above three methods are, they pale in comparison to the full audit one would be able to conduct with the whole, detailed dataset at one’s disposal. At the moment, though, the incentives for keeping data private (including, perhaps the fear that someone will find errors in your published work) clearly outweigh the Mertonian reasons for sharing it.

 

 UPDATE: A related post from Are Experts Real? by Alvaro de Menard.