Some interesting statistics about money and marriage from The Economist:
Marriage itself is “a wealth-generating institution”, according to Barbara Dafoe Whitehead and David Popenoe, who run the National Marriage Project at Rutgers University. Those who marry “till death do us part” end up, on average, four times richer than those who never marry. This is partly because marriage provides economies of scale—two can live more cheaply than one—and because the kind of people who make more money—those who work hard, plan for the future and have good interpersonal skills—are more likely to marry and stay married. But it is also because marriage affects the way people behave.
This economic difference also manifests when children are used as the measurement:
Most children in single-parent homes “grow up without serious problems”, writes Mary Parke of the Centre for Law and Social Policy, a think-tank in Washington, DC. But they are more than five times as likely to be poor as those who live with two biological parents (26% against 5%). Children who do not live with both biological parents are also roughly twice as likely to drop out of high school and to have behavioural or psychological problems. Even after controlling for race, family background and IQ, children of single mothers do worse in school than children of married parents, says Ms Hymowitz.