Mostly programs will either have a positive return on investment in the conventional sense (e.g. hire more tax inspectors, make more tax income), or have an ar

Mostly programs will either have a positive return on investment in the conventional sense (e.g. hire more tax inspectors, make more tax income), or have an arguable, positive overall long-term return on investment hopefully, (e.g. infrastructure spending, sending smart kids to college) or will enjoy widespread public support and provide non-monetary benefits, (e.g. public parks, libraries, maternity leave) or will be widely accepted as a core function of government (e.g. police and military), or a morally good and virtuous act (e.g. caring for the disabled, foreign aid) or will be the pet project of someone powerful, semi-useful, and inexpensive enough no-one cares to fight them over it (e.g. opera subsidy) or will convince people they're one of the above regardless of the truth of the matter or will be at risk of cancellation.