From the Game Rules:

HOW DO PLAYERS ON OBOZO’S WELFARE PROMENADE CONTINUE TO COLLECT THEIR MONTHLY GRANTS? Each time a player makes it to the First of the Month or passes it, he or she receives the basic monthly grant of $1,000, plus $300 for each out-of-wedlock child acquired (this figure includes a cash equivalent for food stamps and medical expenses), plus the amount specified by any Welfare Benefit cards drawn.

From the Game Rules:

IS THERE A LIMIT TO THE NUMBER OF OUT-OF-WEDLOCK CHILDREN A PLAYER ON OBOZO’S WELFARE PROMENADE CAN HAVE? No. It is possible, though improbable, to land on 16 Have Out-of-Wedlock Child blocks in 2 trips around Obozo’s Welfare Promenade. Sixteen out-of-wedlock children may be uncommon but not unheard of. A welfare recipient in Baltimore, for example, is on record as having 22 out-of-wedlock children, all by the age of 32. And in turn, some of her out-of-wedlock children now have out-of-wedlock children of their own. This makes Obozo the Marxist clown and his Government Dependency Czar very happy.