Equation 21 · Part 1 · When Generation Becomes Free, Attention Becomes the Scarce Good
Symbol s
What this part means
the signal level.
Its job in the formula
s is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Full expression→Symbol s→Article meaning
Where the article explains it
In the standard notation, with signal level s and type increasing in ability, the single-crossing condition is
The passage around this formula
Spence’s contribution was to explain how information can cross the asymmetry without direct verification. An agent takes a costly action — in his original case, education — and the action separates types only under a specific condition: the marginal cost of the signal must be lower for the type the signal is supposed to identify. In the standard notation, with signal level s and type increasing in ability, the single-crossing condition is
Learn the underlying idea
A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.
Open the illustrated variables: a letter stands for a value guide →
See this notation across published equations →
Sources cited in the article section
These citations provide research context; check each source for the exact claim it supports.