1200+ words is a lot especially when you have two essays to get done, but if you have the capacity to think fast of relevant economic concepts and at the same time a fast hand writing then go ahead
Of course you can get 18+ for a 1000 word essay, could also for ~900 if you are very concise and to the point.
I wouldn't write too much cause there is a risk of ending up in a hand-writing diarrhoea type of situation ya know
I would say, write a plan that has a good amount of ideas that will answer the question precisely then start writing your essay. They don't look for quantity (but of course that doesn't mean write only a page or two), they want to know that you can answer the question with great focus, no blah-blah's.