Equation 5 · Part 1 · Demography, Migration, and Urban Futures in Practice: An Advanced Technical Guide
Symbol P
What this part means
the population count.
Its job in the formula
P 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 P→Article meaning
Where the article explains it
where P is the population count, S is the age-and-sex-specific survival ratio for that interval, and M is net migration assigned to that cohort during the interval.
The passage around this formula
where P is the population count, S is the age-and-sex-specific survival ratio for that interval, and M is net migration assigned to that cohort during the interval. The youngest cohort in each step is not aged forward from an existing cohort; it is generated fresh from the number of births, which is itself the product of age-specific fertility rates applied to the female population of childbearing age, by convention ages 15 to 49 [ 1 ] .
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.
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Sources cited in the surrounding passage
These citations provide research context; check each source for the exact claim it supports.