I didn’t know about the song lol, for a second I thought he had a career outside of football

Thiago Silva (?)

This work was led by Abdurahman Maroouf, who did a fantastic job over the summer (!)

With: Kevin T Greene, Stefan Feuerriegel, @jshapiro.bsky.social

It was also made possible by this amazing initiative, the Research Accelerator (researchaccelerator.org).

Putting it together:

Short-form video platforms act as a structural driver of mobile usage.

They don’t just change what people watch; they change how much and how often they use their phones: longer total use, shorter breaks, more entrenched checking routines.

But is this about short-form video or about TikTok?

We repeat the analysis in a later period when Instagram and Facebook also had short-form video. There, differences between TikTok adopters and others vanish—suggesting the effect is about the format, not the specific app.

When does this extra usage happen?

Effects are concentrated during the day. We find no consistent evidence that short-form video increases nighttime mobile use beyond what other social media already does.

Who is most affected?

Short-form video especially pulls in people who previously used their phones less:

Low-intensity users: ≈31% increase in total mobile duration

High-intensity users: ≈14% increase

Main finding: short-form video platforms meaningfully amplify mobile use.

After adoption, total mobile duration increases by ≈17% (about +28 minutes/day for the average user), and the average time away from the phone (TAP) shrinks by ≈20%.

We use a matched, stacked DiD design:
- Treatment: people who adopt TikTok
- Control: people who adopt Instagram or Facebook in the same period

Outcomes:
- total daily mobile duration
- number of sessions
- average time away from phone (TAP)

We use passively collected, individual-level data from a large U.S. mobile panel (N=1,764), tracking every app and website people used on their phones.

We focus on a period when TikTok offered short-form video and Instagram/Facebook did not! Short-form video was the key diff!

Short-form video raises concerns about compulsive use and well-being, but most evidence is correlational.

We ask a simple question: What happens to people’s overall phone behavior when they start using a short-form video platform?

Do they just swap one app for another?

I argue that if we consider these three points, we find that labeling with LLMs is neither trick nor treat. Treated as measurement instruments, their value lies in forcing us to confront uncertainty we once ignored; not in completely eliminating it.