I've really enjoyed most of Harford's books (see other reviews here and here), and this one was at least as good as any of the others. Harford has a talent for pulling together appropriate anecdotes to illustrate the points he is making. And the overall point of this book is the importance of using trial and error to adapt to challenges. In other words, it is increasingly important to identify new ways of dealing with challenges as (if not before) they arise, if we want to be successful.
Towards the end of the book, Harford identifies three essential steps for adaptation (the 'Palchinsky principles', named for a Russian engineer who identified problems in Russian coal mines in the early 20th Century):
First, try new things, expecting that some will fail. Second, make failure survivable: create safe spaces for failure or move forward in small steps... And third, make sure you know when you've failed, or you will never learn.The first principle makes a case for constant innovation, experimentation, and rigorous testing, even when things are going well. If it isn't broken, it can still be fixed to work better. The second principle is about managing risk. If you fail, do so early before it becomes catastrophic. Which is where the third principle comes in. Identifying when something you try has failed and not feeling beholden to continue it is challenging, but essential.
These are good principles for business, and in the final chapter Harford illustrates how they can be applied for individuals. I highly recommend this book as a good read, not because of the economics content (of which there is a fair amount), but because of its more general applicability. Enjoy!