  The concept of Probability of Causation (PC) is critically important in legal
contexts and can help in many other domains. While it has been around since
1986, current operationalizations can obtain only the minimum and maximum
values of PC, and do not apply for purely observational data. We present a
theoretical framework to estimate the distribution of PC from experimental and
from purely observational data. We illustrate additional problems of the
existing operationalizations and show how our method can be used to address
them. We also provide two illustrative examples of how our method is used and
how factors like sample size or rarity of events can influence the distribution
of PC. We hope this will make the concept of PC more widely usable in practice.
