Professor Lijphart, having read your book and looked at your research, I'm struck by how much work goes into being able to make a summary statement such as the one you just made. You must have had large team studying empirically the results of 36 democracies over as long a time span as you looked at, from the end of the Second World War until now.
This is just a pragmatic question that occurs to me. How does one have the confidence to say, “This isn't an opinion, this is the fact”?