In US, joint property is just that, if one spouse dies, the other spouse received 100%. Think about the family car with two people's name on it, they are jointly owned by the couple, one party dies, the other party automatically takes over.
At least I think US rule is simpler. If following Chinese rule strictly, if one spouse dies, the other family member could legally go after 50% of everything, such as house, car, television etc. That will create havoc for the surviving spouse.