I believe SDO is incorrectly calculated as reader number 7 has 0 for both outcomes, observed and counter factual, with and indicator in 1, so you should add 3 ones and 1 zero and not 4 ones in the selection bias example, am I right? I believe that it would be corrected if you interchange indicators between records 6 and 7.

## Estimating Average Treatment Effects

I believe SDO is incorrectly calculated as reader number 7 has 0 for both outcomes, observed and counter factual, with and indicator in 1, so you should add 3 ones and 1 zero and not 4 ones in the selection bias example, am I right? I believe that it would be corrected if you interchange indicators between records 6 and 7.

There are expectation operators missing in the selection bias equation