Have your folks given you cash or promised to leave you money after they're gone? If so, they may think of such gifts as a good. They decide whether to spend their money on fun, food, drink, cars, or give money to you. Hmmm. Altonji and Villanueva (2007) estimated that, for every extra dollar of expected lifetime resources, parents give their adult offspring between 2¢ and 3¢ in bequests and about 3¢ in transfers.
Those gifts are about one-fifth of what they give their children under 18 and spend on their college education. Illustrate how an increase in your parents' income affects their allocations between bequests to you and all other goods ("fun") in two related graphs, where one shows an income-consumption curve and the other shows an Engel curve for bequests.