a : the time of life at which some particular qualification, power, or capacity arises or rests
Love this photo.
Efficacy is the capacity to produce an effect.
If you take the very simplest forms of the two words then they are not really related!!! Yet when it comes to work and interviews the governments of the world have had to produce legislation so that discrimination due to age doesn't occur. I think it is more of a western attitude towards older people than a global problem and I believe that it is a part of the obsession with capitalism. As we age then we are seen as being less efficient.
In fact you just have to look at footballers as an example of how untrue that can be.
Ryan Giggs Kevin Phillips
These two lads are approaching their 40th year and yet are still making excellent contributions at the highest levels. Giggs will be 40 in November and no one seems to know how old Kevin Phillips is!
There are others I could name who are still playing and are much sort after not for their pace and power but more for their efficiency and guile.
It is not much of a stretch to realise that an effective team needs a balance of age and experience with speed and enthusiasm. The argument of Age v Efficacy should not be in question as it is with writing. When you look at writers round the world age constructs no barriers and in fact that is true in all branches of art it has to do with imagination. Imagination is the greatest power available to human kind and if there is a relationship between years on the earth and imagination then it would err on the side of the more experienced. I do not think that there is any meaningful correlation.
So if you wish to write then do so - remember you eat the elephant one mouthful at a time. If you want to write then allow your imagination to roam in all the corners of the earth and your mind. I would only add to that whenever you have the opportunity to scotch the negative attitude there exists towards age do so. There is a great line that I have heard quoted frequently in recent times and that is
'age is just a number'
and from a writer:-