So said Albert Einstein.
Financial modellers would do well to remember this.
I recently sent out a questionnaire asking what the respondents most commonly used functions were. 40% cited INDEX(MATCH), 40% SUMIF and 20% OFFSET.
Whilst all of the above functions have their uses, I would not classify any of these as commonly needed. Whatever happened to the basics such as logical statements, MIN and MAX? Some may also be thinking of IF functions but I’m not a great believer in these either. Yes, IF functions can perform many jobs but they are certainly long-winded and usually replaceable with more efficient options.
The problem is that some financial modellers assume complexity, even when none exists. One of my favourite complexity-related stories is from behavioural economist Dan Ariely. He tells of a locksmith whose clients were impressed when, as an inexperienced beginner, he took half an hour to open a lock. When he honed his skills and was able to complete the task in a fraction of the time, the clients would quibble about the payment.
I often come across formulae in models that are far too complex for the job in hand. Slim your formulae down, use suitable functions and don’t litter your models with unnecessary complexity. Not only will it save time but it will also give other people a chance of understanding what it is you are trying to calculate.
In summary, keep it simple.