Show how the classical two-way split sits inside the four-way one

The natural direct and indirect decomposition is not a rival of the four-way split; it is the four-way split with two pairs already summed. CDE + INTref is the pure direct effect and PIE + INTmed the total indirect effect, so the older decomposition is recovered exactly and the interaction it was hiding becomes visible.

Usage

Vivkt(X, M, Y, Cc = NULL, a = 1, astar = 0, m = 0)

Arguments

X

Exposure.

M

Mediator.

Y

Outcome.

Cc

Optional covariates; read at their means.

a, astar, m

Exposure contrast and controlled mediator level.

Value

List with estimate, pde, tie, cde, intref, intmed, pie, check, n.

Details

Formula: PDE = CDE + INTref, TIE = PIE + INTmed, TE = PDE + TIE.

References

VanderWeele, T. J. (2014). Epidemiology 25:749-761; Robins & Greenland (1992) Epidemiology 3:143-155; Pearl (2001) UAI 17:411-420.

Examples

Vivkt(X = 5L, M = 5L, Y = c(1, 2, 3, 4, 5, 6, 7, 8))
#> $estimate
#> [1] 0
#> 
#> $pde
#> [1] 0
#> 
#> $tie
#> [1] 0
#> 
#> $cde
#> [1] 0
#> 
#> $intref
#> [1] 0
#> 
#> $intmed
#> [1] 0
#> 
#> $pie
#> [1] 0
#> 
#> $check
#> [1] 0
#> 
#> $n
#> [1] 8
#> 
#> $method
#> [1] "Two-way and four-way decompositions together"
#> 
#> attr(,"class")
#> [1] "morie_rich_result" "list"