Non inversibilité des salaires nets post-2019

[pzuldp]

Hi there!

I really enjoy OpenFisca-France-Data, but I recently encountered an issue.

Here is what I did:

I tried to invert the net wage of cadres post 2019.

Here is what I expected to happen:

Be able to do it.

Here is what actually happened:

I realized that the formula is non invertible and I am looking for options.

Here is data (or links to it) that can help you reproduce this issue:

The CET (cotisations equilibre technique) exists since 2019. It kicks in at 1 PSS in a non-marginal way, contrary to practically all other social contributions.
This means that :

• a gross wage of 1 PSS will induce a CET of 0
• a gross wage of 1 PSS + 1 euro will induce a CET computed on 1 PSS + 1 euro (so around 5 euros per month)

As a consequence : two identical net wages can correspond to two different gross wages , as there is a non-monotonicity in the net = f(gross) function.

I am not sure what to do here.

Context

I identify more as a:

• Economist (I make microsimulations with real populations).

[pzuldp]

pour mémoire @clallemand et @benjello