Two unemployed partnered parents will get more between them than an unemployed single parent will get alone. But each of the two partnered parents get less than the single parent. The idea is that a couple living together has less expenses than an unpartnered person. (They can share a room, so less rent. They share meals, so one lot of cooking rather than two.) I disagree with this concept because two single people could live together and make the same savings (but are not likewise penalised in their benefits).