computep function

Computes individual and pairwise treatment assignment probabilities.

Of limited interest to most users, the computep function plays an internal role in 2-sample and stratified sensitivity analyses. The computep function is equations (9) and (10), page 496, in Rosenbaum and Krieger (1990). The computep function is from the senstrat package.

computep(bigN, n, m, g)

Arguments

• bigN: Total sample size in this stratum.
• n: Treated sample size in this stratum.
• m: The number of 1's in the vector u of unobserved covariates. Here, u has bigN-m 0's followed by m 1's.
• g: The sensitivity parameter $\Gamma$, where $\Gamma \ge 1$.

Returns

• p1: Equation (9), page 496, in Rosenbaum and Krieger (1990) evaluated with u[i]=1.

• p0: Equation (9), page 496, in Rosenbaum and Krieger (1990) evaluated with u[i]=0.

• p11: Equation (10), page 496, in Rosenbaum and Krieger (1990) evaluated with u[i]=1, u[j]=1.

• p10: Equation (10), page 496, in Rosenbaum and Krieger (1990) evaluated with u[i]=1, u[j]=0.

• p00: Equation (10), page 496, in Rosenbaum and Krieger (1990) evaluated with u[i]=0, u[j]=0.

References

Rosenbaum, P. R. and Krieger, A. M. (1990) doi:10.2307/2289789 Sensitivity of two-sample permutation inferences in observational studies. Journal of the American Statistical Association, 85, 493-498.

Rosenbaum, P. R. (2002). Observational Studies (2nd edition). New York: Springer. Section 4.6.

Author(s)

Paul R. Rosenbaum

Note

The function computep is called by the function ev.

Examples

computep(10,5,6,2)