  The ideological asymmetries have been recently observed in contested online
spaces, where conservative voices seem to be relatively more pronounced even
though liberals are known to have the population advantage on digital
platforms. Most prior research, however, focused on either one single platform
or one single political topic. Whether an ideological group garners more
attention across platforms and/or topics, and how the attention dynamics evolve
over time, have not been explored. In this work, we present a quantitative
study that links collective attention across two social platforms -- YouTube
and Twitter, centered on online activities surrounding popular videos of three
controversial political topics including Abortion, Gun control, and Black Lives
Matter over 16 months. We propose several sets of video-centric metrics to
characterize how online attention is accumulated for different ideological
groups. We find that neither side is on a winning streak: left-leaning videos
are overall more viewed, more engaging, but less tweeted than right-leaning
videos. The attention time series unfold quicker for left-leaning videos, but
span a longer time for right-leaning videos. Network analysis on the early
adopters and tweet cascades show that the information diffusion for
left-leaning videos tends to involve centralized actors; while that for
right-leaning videos starts earlier in the attention lifecycle. In sum, our
findings go beyond the static picture of ideological asymmetries in digital
spaces and provide a set of methods to quantify attention dynamics across
different social platforms.
