I completely understand your situation. I found myself in the exact same one, that is, wondering if I should continue making buy-ins or not. As you say, if we knew our future, that would be easy! For everything else, there’s modelling There are a lot of variables involved though, and as with every model out there, it is heavily dependent on assumptions (I’m a pension actuary, so I’m painfully aware of that fact!). Those are not necessarily financial assumptions only though, like expected returns, but also personal ones, like whether you might leave Switzerland and when. That’s why some people will conclude that buying into their pension fund is a ridiculous idea, while some might see it as a financially reasonable thing to do.
My point is that one could determine every year or so if your parameters (personal situation and assumptions) still make buy-ins financially reasonable or not. You’d have to take into account things like expected return of your pension fund (you seem to be in an autonomous one, judging by your historical returns), investment horizon until your retirement/departure, marginal tax rate, personal expected return, dividend/capital gain proportion, etc. I personally use a simple spreadsheet that capture most of these variables in order to help make that decision. I’d be more than happy to share (without any guarantees!) if you’re interested. As I said, it’s heavily dependent on assumptions, but in a nutshell (and assuming you get a better return outside the fund), the shorter the investment horizon, the more beneficial the buy-in is.
Of course if we want to make things more interesting, we should take into account volatility and/or uncertainty (sorry, can’t resist ). Indeed, the simple tool I mentioned is only deterministic, and as such doesn’t capture the wide range of possible outcomes, which one could see better with a stochastic projection (even more assumptions sadly ). For instance, buying-in today gives you an almost guaranteed tax return in the very short-term (in an investment vehicle, the pension fund, that has a very peculiar return profile—positively correlated to the stock market, but with a floor), whereas your personal investments outside of the pension fund could return a lot more, albeit with more uncertainty/volatility. At this stage, even without stochastic modelling, every individual’s risk tolerance and capacity for it will come into play.
Hope that makes some sense!