This isn't a comparison of whether adding #OpenToWork to your profile changes the likelihood of being hired. It's a comparison of whether people who chose to ad

This isn't a comparison of whether adding #OpenToWork to your profile changes the likelihood of being hired. It's a comparison of whether people who chose to add OpenToWork to their profiles were more likely to be hired. It's totally possible that one of the populations is more/less hireable than the other, and OpenToWork is a correlated, but not causal factor.