← All parts of this equation

Equation 13 · Part 6 · Why We Punish Strangers: The Evolution of Human Cooperation

subtraction

wp=k(1−x−y)w_p = k(1 - x - y)
subtraction

What this part means

Subtract the following term or group from the preceding one. A leading minus marks a negative quantity.

Its job in the formula

Subtract the following term or group from the preceding one. A leading minus marks a negative quantity.

The passage around this formula

The first is cultural group selection, formalized by Robert Boyd, Herbert Gintis, Samuel Bowles and Peter Richerson. Their starting problem is that punishing free-riders is itself a public good — everyone in a group benefits if free-riders are deterred, but only the punisher pays the cost of deterring them, so a population of willing punishers should in principle be invaded by cooperators who never bother to punish, a “second-order” free-rider problem sitting on top of the first [ 9 ] . Their proposed way out rests on an asymmetry between the two roles. A plain cooperator who does not punish pays a fixed cost, call it c , simply by cooperating, regardless of how many other group members…

Read this part in the article →

Learn the underlying idea

Addition combines quantities; subtraction measures the signed difference between them. Parentheses show what is combined before the rest of the expression is evaluated.

Open the illustrated addition and subtraction in an equation guide →

Sources cited in the surrounding passage

These citations provide research context; check each source for the exact claim it supports.