Why does income for a family tend to go up when two single persons marry?

you are combining two people income into one household

Explanation:

Because if both of them work, the family income is the sum of both of their individual incomes

answer; the best answer is (demand);

acts of terrorism occur globally. the united nations global counter-terrorism strategy was created in order to build adequate systems of support and solidarity with victims of terrorism. here´s a summary of the proposed key themes: the importance of giving victims a face and a voice; protecting their dignity; giving victims legal status and defending their legal rights; providing victims with medical, psycho-social and financial support; building solidarity with victims; improving media coverage of victims; and focusing on the link between victims and counter-terrorism efforts more generally.