My favorite example of Simpson's paradox: On average, in the United States, houses without central AC cost more than houses with central AC. When you break it

My favorite example of Simpson's paradox: On average, in the United States, houses without central AC cost more than houses with central AC. When you break it down by state it turns out this is almost entirely due to lots of expensive houses without central AC in California. In every single state houses with central AC are more expensive than houses without, but California with its high real estate prices and temperate climate skews the national averages.