Gradients introduce a tremendous measurement problem.
It's more efficient to provide services gratis (think of community-funded fire, police, education, and parks services), and apply the measurement problem to the revenue side through progressive taxation of income or assets (wealth).
This also creates a larger political constituency for the service as everyone benefits. This was the thinking behind a universal social security system, rather than providing a needs-based system.
There's a fair argument for abandoning free market principles when one considers both that children are literally outside the market (they have no independent wage or income), and that the positive externalities of rearing and educating children redound on the local community. (Well, net of out-migration / brain drain, which is in fact A Thing, and not a minor consideration in many cases.)
Oh, and there's the deadweight loss of those who would qualify for a benefit (under law) but fail either to jump through the proper bureaucratic hoops, or who do hoop-jump, but are still denied benefits, whether through bureaucratic error, inefficiency, corruption, or other reasons.
TFA describes the first circumstance.
Patio11 has noted that the optimum level of fraud is non-zero, a point picked up by Cory Doctorow as well:
Means-tested benefits are something you really want to think through before advocating. Gradient-benefits or sliding-scale benefits are forms of means testing.
I don't know if there's well-developed theory of when means-testing should or shouldn't be applied. There are some surprising arguments from surprising positions (a quick glance at the beginning of this National Affairs article, from a conservative position, is against means-testing, though it's also critical of social welfare programmes generally: <https://www.nationalaffairs.com/publications/detail/means-te...>).
I'd suggest that means-testing / sliding scale works better or is more appropriate where:
- It's applied locally rather than globally, to small populations in regular contact and where even eyeball assessments are likely roughly accurate.
- Where resources and/or services offered are limited.
Provision of sliding-scale services (healthcare, dental, vision, legal assistance) often falls under such cases. School lunches might, but the risks of abuse and long-term community harm are high.
It's more efficient to provide services gratis (think of community-funded fire, police, education, and parks services), and apply the measurement problem to the revenue side through progressive taxation of income or assets (wealth).
This also creates a larger political constituency for the service as everyone benefits. This was the thinking behind a universal social security system, rather than providing a needs-based system.
There's a fair argument for abandoning free market principles when one considers both that children are literally outside the market (they have no independent wage or income), and that the positive externalities of rearing and educating children redound on the local community. (Well, net of out-migration / brain drain, which is in fact A Thing, and not a minor consideration in many cases.)