Most likely the baseline is normalized to zero, and then the Y axis is percentage growth from the baseline.  So 0.2 is 20% increase from the base period.



SimpleStacker

Figure 2: Time Series of Junior and Senior Employment in Sample Firms

Notes: This figure plots the average number of junior-level workers and senior-level workers in our sample of firms over time, normalized to 1 in January 2015. We define “junior” workers as those in Entry- or Junior-level positions, and “senior” workers as Associate level and above (see Section 3.1 for details)

Generative AI is reducing the number of junior people hired

Scoresby

The graph text:

> Figure 2: Time Series of Junior and Senior Employment in Sample Firms
Notes: This figure plots the average number of junior-level workers and senior-level workers in our sample of firms over time, normalized to 1 in January 2015. We define “junior” workers as those in Entry- or Junior-level positions, and “senior” workers as Associate level and above (see Section 3.1 for details)

I note 2 things:

1. Something is odd about that Y axis
2. WTF happened in 2020? Oh. lol