# If-Only vs. Ceteris Paribus

This is my understanding of the distinction between the “If-Only” and “Ceteris Paribus” ego defence mechanisms: “If-Only” is “If only X had occurred, I’d be right” “Ceteris Paribus” is “If only X hadn’t occurred, I’d be right” The first is about something expected not occurring, and the other is something unexpected occurring. Is that right, or is there a different distinction?

Yes this is how I understand it.

I understood the distinction differently If Only If you considered the factor in your assumptions / model but the value or outcome of the factor varies from your expectations and that threw your estimate off course Ceteris Parabus If you had not considered the factor in you assumption / model but if “came out of the blue” to effect you forecasted outcome My distinction is only loosely analogous to yours - I also recall if only being characterized as “if only they had listened to you” - so this collectively yield a color I refer to as CFA Grey. This is in the top decimal of my top 100 of useless mind numbing distinctions that I will have faced in life for no other purpose than to build my CFA Character.

The main distinction I believe is with the “If Only” you had what you thought the variable or “X” would do built into your forecast - for instance, if only the dollar had appreciated in comparison to the euro like I thought… Whereas “Ceteris Paribus” occurs when something happens that was not built into your forecast, like - if the government hadn’t lifted the tariffs on the import, then my domestic industry would have continued to grow…

I think Ellejay’s explanation is correct. If only - is about a variable you considered in your forecast. Ceteris Paribus - is about varaibles that you didn’t consider in your forecast.

This can’t be worse than the fundamental law of investing Information Ratio = (Information coefficient) (# of independant decisions^(1/2))

BiPolarBoyBoston Wrote: ------------------------------------------------------- > This can’t be worse than the fundamental law of > investing > > Information Ratio = (Information coefficient) (# > of independant decisions^(1/2)) Ya, I hate this kind of “pure” memorization issues (without knowing why it is so and/or how it is derived, and those clauses in GIPS of requirements and/or recommendation with dates valid, some terminologies without tangible/clear definitions" .