It all depends on what variety of tree your olive(s) are. There are hundreds of varieties throughout the world (think apple trees) and about 150 are cultivated in a form or other. Some trees are for eating olives (like ours) others, smaller fruits, are for pressing for oil. A worrying and...
My Spanish neighbour let me into her secret regarding processing olives. Cut a cross in the top of each olive (saves bruising them with a wooden mallet) and make up a brine - this is the foolproof recipe; Place a fresh egg into a clear demijohn or similar glass vessel, make a salt brine...
It's very noticeable here that since the cost of EV olive oil rocketed (a decent Arbequina, the nicest on bread, is now 10 - 14 euros a litre) the sales have dropped considerably. Coupled with the decrease in price of sunflower oil, now down to 6.50 euros for 5 litres a lot of the Spanish have...
Not so much a shortage of anchovies Harry - more the cost of production and canning them in olive oil. A small can (170gm) of quality ones now 8 euros more than double last years price.