I don't know what that means, but it can't refer to something like a quotient of national (or global) happiness. It's patently absurd to think of measuring individual degrees of happiness, let alone summing those measurements. Suppose the government takes from A (making him miserable) and gives to B (making him joyous). Does B's joyousness cancel A's misery? Only if you're B or a politician who has earned B's support by joining in the raid on A's bank account.
Something like "the greatest good for the greatest number" can come about only in a representative democracy, where political bargaining about legitimate government functions leads to a compromise that's satisfactory to most members of the body politic. An example would be an agreement to have a defense budget of a certain size and to authorize (or not) the use of the armed forces for a particular defensive objective.
But representative democracy has adopted modern liberalism's conception of the greatest good for the greatest number, which is to tell us how we should live our lives -- for our own good, of course. It's busy-body government. It may yield the greatest psychic good to those who make the rules, but it yields untold economic harm to almost everyone, including those who make the rules. (See the preceding post.)