I can think of all kinds of interesting descriptive stats you could extract. Graphs of the times series of purity results, for different types of PEDs, or for different countries. One could look for structural breaks in the time series around events such as government crackdowns. You could even try to run some regressions to try and explain the differences in purity results and/or the number of samples sent in from different countries, like the legal status there (dummy), population, density of gyms, geographical distance (shipping cost/customs related), etc., with time fixed effects if there's enough years. Oh yeah, one could also judge source popularity over time by the number of sent-in samples, control for their reimbursement policy, relate it to the probability of source exit (scam vs bust), which could be a nice addition to a game theoretic model. And there's more clever stuff which I don't want to get into here.
As I said, I'd be happy to agree to give you a right to review manuscripts prior to submission/publication to ensure confidentiality. You could also be a coauthor of course.
