You start with a picture. This is the partial plot of your $input against $outcome. You've waved a magic wand that solves all identification issues, so this is the causal effect.[…]
Clearly there's variation you can't explain with $input, because other stuff is going on as well. The world isn't monocausal.
Anyway.
Your book has to sell with a popular audience, so you can't just print out regression tables. You have to tell a story. Well, the data in a regression encodes a story: behind the data points in a scatterplot is history of policy across observation units. So you pick out a few case studies and center the book around an examination of those case studies.
And you sell your book. And people review it. And everyone wants to take a piece out of you.
Some commentators scoff at your $input. Look, they say, $input doesn't do anything to affect $output. Look at these case studies. We vary $input by a factor of three, and nothing changes to $outcome.
Other commentators point out that many observation units with roughly the same level of $input have massively different outcomes. Look at these case studies. All of these observation units have similar levels of $input, but their outcomes differ dramatically. What gives?
Some smartass commentators even turn the tables on you. Look at these case studies. Now it appears that $input has a negative effect on the outcome! How could anyone take your new book seriously?
(obviously, @JustinSandefur and chart author Arvind Subramanian are not naive critics; but the general point here)
^it is possible to hold two thoughts in one’s skull at the same time… to respect the genius and simultaneously to also recognize the flaws where they exist
More on Acemoglu, Johnson, and Robinson
Meta commentary
On one of the chemistry Nobel laureates:
^💀
^Tyler Cowen (2009), “Two factors shaping the economics profession today”:
Empirical work has a shorter half-life than does theory, at least on average. Yet most people today, including at top schools, do empirical work. There will be fewer giants and more middling-size figures of temporary import. If you tenure a top empirical economist, what does your department look like when he or she is 60? What percentage of these people are skilled enough, or care enough, to continue reinventing themselves? Maybe some top departments won't look so top in twenty years' time.
IO jokes
^still waiting on the BLP prize…
Memes, jokes
If you’ve been on the econ side of the internet long enough, you may recall…:
Love the Inty comment, certified classic