Statistically difference between two slopes

Dear Knimers,
I have another situation, for which I ask for your help. This time, I need to choose a statistical test to discover if the slopes of two curves (each one of them is visually aligned with a straight line) are significantly different (or not).
Indeed, these curves are two parts of the same curve (public expenses “before” and “after” the Covid onset). I have split the original dataset into two separate files:
a) MA-SumExps-jan2017-jan2020.csv (1.1 KB)
b) MA-SumExps-mai2020-jun2023.csv (1.2 KB)
And the whole original dataset may lead to the following graph:


These datasets depict two moments in the time series for the target public expenses, where “Date” is the independent variable.
Can someone help me to choose which test might lead me to know if there is (or not) a statistical difference between these two slopes?
Thanks for any help.
B.r., Rogério.

Hi @rogerius1st -

There’s not a node to do what you want right out of the box, so you’ll probably need to do a bit of scripting. You might find this helpful:

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