  The COVID-19 pandemic has had a wide-ranging impact on information workers
such as higher stress levels, increased workloads, new workstreams, and more
caregiving responsibilities during lockdown. COVID-19 also caused the
overwhelming majority of information workers to rapidly shift to working from
home (WFH). The central question this work addresses is: can we isolate the
effects of WFH on information workers' collaboration activities from all other
factors, especially the other effects of COVID-19? This is important because in
the future, WFH will likely to be more common than it was prior to the
pandemic.
  We use difference-in-differences (DiD), a causal identification strategy
commonly used in the social sciences, to control for unobserved confounding
factors and estimate the causal effect of WFH. Our analysis relies on measuring
the difference in changes between those who WFH prior to COVID-19 and those who
did not. Our preliminary results suggest that on average, people spent more
time on collaboration in April (Post WFH mandate) than in February (Pre WFH
mandate), but this is primarily due to factors other than WFH, such as
lockdowns during the pandemic. The change attributable to WFH specifically is
in the opposite direction: less time on collaboration and more focus time. This
reversal shows the importance of using causal inference: a simple analysis
would have resulted in the wrong conclusion. We further find that the effect of
WFH is moderated by individual remote collaboration experience prior to WFH.
Meanwhile, the medium for collaboration has also shifted due to WFH: instant
messages were used more, whereas scheduled meetings were used less. We discuss
design implications -- how future WFH may affect focused work, collaborative
work, and creative work.
