"Por favor hay que votar en estas leyes."
This bonus is a reward the country pays from its budget based on a town's population. The value is how much each reward pays out.
Raising the value pays a bigger reward each time, which makes the rewarded action more attractive but spends the country budget faster.
Lowering the value pays a smaller reward each time, which saves the country budget but gives citizens less incentive.
This is a neutral explanation to help you decide — it doesn't favor either side.