TL;DR: Past experience does count. There are bonuses too. I estimate 2600€/month net for the given info.
The question is directly related to the application of the French decree n°2009-462 (last modified in 2022).
In short, someone newly recruited in one of the MCF/PU corps can benefit from some of their experience to start at an echelon above 1.
Some case sheets are available, though they are not up to date.
Recruiting establishments themselves have access to a "calculator" where they enter the recruit's info to get a number of years.
That calculator's source code is even available thanks to the efforts described here.
My interpretation of the main rules in the decree (for an MCF who is not already a public servant):
- (Article 5-1) You get one (bonus) year just for holding a doctorate.
- (Article 4) If your doctoral work was financed via a work contract under a public agreement/receiving public aid (mostly for French CIFRE theses, but possibly applicable to other cases in France or abroad), it is accounted for up to six years, after appreciation by the academic council (or equivalent).
- (Article 5) If your post-doctoral (research) work was financed via a work contract, it is accounted for (usually) in full, after appreciation by the academic council (or equivalent).
- (Article 8) If your work was funded via some specific French mechanisms (doctorant contractuel, ATER, allocataire de recherche, moniteur), it is accounted for in full.
- (Article 15) If not concerned by article 4 and/or 8, your doctoral work can instead be accounted for a flat two years.
- (Article 15) Any eligible part time activity is accounted for on a pro rata basis. You cannot take into account the same period twice (or more).
- (Articles 10-14) There are other articles taking into account some other relevant work experience, usually for half or two thirds (or other fun fractions) of the time.
- Knowing the seniority leads to the computation of the echelon, but any leftover seniority is kept as progress towards the next echelon.
Since some appreciation is built-in the application of certain articles (e.g. 4 and 5), it appears difficult to give a definitive answer working every time and for every establishment.
Based on the case of a 5-year doctorate in Switzerland and 3-year postdoc in the US, it seems likely for the full 8 years (= 9 years with "PhD bonus") to be taken into account.
If it is the case there were issues regarding the appreciation of the contracts/fundings/nature of the work, the doctorate should still be worth at least 3 years (2 years flat rate + "PhD bonus") and the postdoc at least half its duration (= 4 years and a half total). The best case means echelon 4 six months from echelon 5, and the presumed worst case means echelon 3 some way towards echelon 4.
Note that the starting salary will indeed be based on echelon 1 (or 2). However, within the first year, HR is supposed to work with you to compute the correct echelon, and pay you back the difference.
That is not all, since the French decree n°2021-1895 introduces a revamped (gross) bonus regime ("RIPEC" with three components, "PEDR" becoming much rarer). The first component of RIPEC is basically just a mensualised standard bonus, it is supposed to evolve from 4500€/year in 2024, to 5200€/year in 2025, to 5800€/year in 2026, to 6400€/year in 2027.
The second component of RIPEC is based on special responsabilities (6k€, 12k€ or 18k€). The third component of RIPEC is based on outstanding personal engagement (from 3.5k€ to 12k€) and is meant to concern 45% of the workforce at a given time (it lasts three years and you cannot get it again for the same reason for one year after that).
That is not all, since the French decree n°2021-1617 describes an annual differential allowance for an MCF which guarantees at least twice the (gross) "SMIC" based on 1607 hours per year.
At the time being, it would mean that an MCF recruited at an echelon below 4 (gross 3189,96€/month, from IM 648) would receive a boost to nearly that (gross 3120,26€/month, from 1607x11,65€/12). If you include the first component of RIPEC in the computation, and since echelon 1 basically does not exist anymore, only someone at echelon 2 would benefit from this, albeit slightly. Since the SMIC may evolve faster than the index point against inflation, this decree remains however an interesting safety net, so to speak.
That is not all, since it is usually possible to teach some "heures complémentaires" paid about gross 41€/hour "equivalent TD". There is apparently a limit of about gross 7.7k€ you could earn this way, but it would roughly mean doubling your teaching load. Often you have no choice but to accept some "heures complémentaires" to be a team player, but too much of them would likely kill your research career.
For an MCF, being promoted to MCF HC or PU (requiring the HDR), etc. is indeed the natural way to increase their salary. Such successful trajectories would actually go hand in hand with eligibility for RIPEC bonuses. (And not so much with a higher than average teaching load.)
In summary, a newly hired MCF with no experience outside a 3-year PhD should get around (gross) 37-39 k€/year. With 8 years of relevant experience, we are looking at (gross) 43k€/year, and 46k€/year within a year.
You basically need to be nearly retired Prof. Groovy McRockstar with high responsabilities to have a shot at more than (gross) 100k€/year.
To give a ballpark of net salaries, this simulator gives some decent results, though you need to piece official info and tools together for more accuracy.
For the numbers in the question, I think 2600-2800 €/month is thus a reasonable estimation, and incidentally around what many new hires would get.
Is the starting salary as an MCF pitiful compared to similar jobs in the CH/US? Quite. Is it as bad as what the "grilles" suggest? Not so bad. Is the starting salary as an MCF sufficient to live decently in France? Sure, but in Paris you would not exactly be dreaming the dream, and/or if you have a spouse who would have a hard time finding a job, and/or children, then it gets rough.