1) Latin phrase 
The term ex-ante (sometimes written ex ante or exante) is a phrase meaning `before the event`. Ex-ante is used most commonly in the commercial world, where results of a particular action, or series of actions, are forecast in advance (or intended). The opposite of ex-ante is ex-post (actual) (or ex post). Examples: The ex-ante (and ex-post) reas.....
Before the fact; that is, before some event has taken place.
Latin for 'beforehand'. In models where there is uncertainty that is resolved during the course of events, the ex antes values (e.g. of expected gain) are those that are calculated in advance of the resolution of uncertainty. Contexts: theory; models
based on anticipated changes or activity in an economy (opposed to ex post).