Data from: The availability of research data declines rapidly with article age

Policies ensuring that research data are available on public archives are
increasingly being implemented at the government, funding agency, and
journal level. These policies are predicated on the idea that authors are
poor stewards of their data, particularly over the long term, and indeed
many studies have found that authors are often unable or unwilling to
share their data. However, there are no systematic estimates of how the
availability of research data changes with time since publication. We
therefore requested datasets from a relatively homogenous set of 516
articles published between 2 and 22 years ago, and found that availability
of the data was strongly affected by article age. For papers where the
authors gave the status of their data, the odds of a dataset being extant
fell by 17% per year. In addition, the odds that we could find a working
email address for the first, last or corresponding author fell by 7% per
year. Our results reinforce the notion that, in the long term, research
data cannot be reliably preserved by individual researchers, and further
demonstrate the urgent need for policies mandating data sharing via public
archives.