CONCEPT
Non-Substitutable Inputs
The class of production inputs for which no combination of alternatives can compensate — the Leontief-structure constraint that explains why AI cannot produce what families need most, regardless of how much else it produces cheaply.
In production theory, substitutability measures the degree to which one input can replace another while maintaining the same output. Some inputs are highly substitutable: a firm can hire more workers or buy more machines and produce roughly the same amount either way. Other inputs are non-substitutable: no combination of alternatives produces the same output. When a commodity requires a non-substitutable input, the production function follows what economists call a Leontief structure, named after Wassily Leontief: output is limited by the scarcest input, regardless of how abundant the others are. The household can have unlimited AI assistance, unlimited market goods, unlimited everything else — and the production of secure attachment remains constrained by the hours of parental presence. The input is irreducible.
In The You On AI Field Guide
The concept is precisely what reveals what AI cannot do inside households, regardless of how much else it can produce cheaply. A family dinner can substitute a restaurant meal for