I think decision making for children comes with growth and responsibility. In the early stage of a child, he/she is naive to allot of things that only the parents can teach him or her. A child could want to make a decision that will cost him or her their future, we've seen such in many scenarios. So what if the child persist they don't want to do that thing you as the parent saw it is best for them, they want to do the contrary because we've given them the right to decision making at their age...
I think in cases like this, one person's decision must have to override the other, and it's definitely not the child's I guess..