Sean J. Taylor (NYU), Lev Muchnik (HUJI), and Sinan Aral (MIT)
Sean J. Taylor (NYU), Lev Muchnik (HUJI), and Sinan Aral (MIT)
(18% of online adults, Pew 2013)
(6% of online adults, Pew 2013)
(665m daily active users, Facebook 2013)
(70m users, Semiocast 2013)
identified author
95% of viewer-comment exposures
anonymous author
5% of viewer-comment exposures
Users were informed this was a site-wide experiment.
Two year study allows us to rule out novelty effects.
\( \Pr(Y_{ijk} = 1| D_{jk}) \sim \alpha_{ij} + \delta D_{jk} \)
ATEI = \( \frac{\Pr(Y_{ijk} = 1 | D_{jk} = 1)}{\Pr(Y_{ijk} = 1 | D_{jk} = 0)} \)
ATEI(x) = \( \frac{\Pr(Y_{ijk} = 1 | D_{jk} = 1, X_{ijk} = x)}{\Pr(Y_{ijk} = 1 | D_{jk} = 0, X_{ijk} = x)} \)
Bootstrap 95% Confidence Intervals for Relative Risk
Comments are highly skewed toward active users, allowing a within-subject analysis.
Active commenters seem to mostly be helped by their identities.
Dramatic positive opinion change for some active users.
Higher reply rates for some commenters when identity is shown.
Usually seen next to high scores → helpful identity.
Usually seen next to low scores → harmful identity.
New viewer subgroup: 4.6x10^5 exposures
New commenter subgroup: 4.9x10^5 exposures
A mechanism for cumulative advantage in ratings?