Today, that taboo is dead. The causal revolution, instigated by Judea Pearl and his colleagues, has cut through a century of confusion and established causality -- the study of cause and effect -- on a firm scientific basis. His work explains how we can know easy things, like whether it was rain or a sprinkler that made a sidewalk wet; and how to answer hard questions, like whether a drug cured an illness. Pearl's work enables us to know not just whether one thing causes another: it lets us explore the world that is and the worlds that could have been. It shows us the essence of human thought and key to artificial intelligence. Anyone who wants to understand either needs The Book of Why.

    People can use economics and they can use statistics and numbers to get at the truth and there is a real appetite for doing so. This is such a BBC thing to say--there’s almost a public service mission to be fulfilled in educating people about economics. When I wrote The Undercover Economist, it was all about my pure enthusiasm for the subject; the book is full of stuff I wanted to say and that is always the thing with the books: they are always such fun to write. Do you think that people these days are generally more economically literate? People are now aware of economics for various reasons. There are the problems with the economy--there is always more interest in economics when it is all going wrong. Where is the border line in your new book between economics and sociology? I don’t draw a border line, and particularly not with the new book. The Undercover Economist was basically all the cool economics I could think of and The Logic of Life was me investigating a particular part of economics. All of the references in The Logic of Life were academic economics papers that I had related--and hopefully made more fun. This new book, Adapt, is very different. I have started by asking what is wrong with the world, what needs fixing, how does it work--and if economics can tell us something about that (which it can) then I have used it. And if economics is not the tool that you need--if you need to turn to sociology or engineering or biology or psychology--I have, in fact, turned to all of them in this book. If that’s what you need, then that’s where I have gone. So I have written this book in a different way: I started with a problem and tried to figure out how to solve it. What specific subjects do you tackle? To be a bit more specific, the book is about how difficult problems get solved and I look at quick change; the banking crisis; poverty; innovation, as I think there is an innovation slow-down; and the war in Iraq. Also, I look at both problems in business and in everyday life. Those are the big problems that I look at--and my conclusion is that these sorts of problems only ever get solved by trial and error, so when they are being solved, they are being solved through experimentation, which is often a bottom-up process. When they are not being solved it is because we are not willing to experiment, or to use trial and error. Do you think companies will change to be much more experimental, with more decisions placed in the hands of employees? I don’t think that is necessarily a trend, and the reason is that the market itself is highly experimental, so if your company isn’t experimental it may just happen to have a really great, successful idea--and that’s fine; if it doesn’t, it will go bankrupt. But that said, it is very interesting to look at the range of companies who have got very into experimentation--they range from the key-cutting chain Timpson’s to Google; you can’t get more different than those two firms, but actually the language is very similar; the recruitment policies are similar; the way the employees get paid is similar. The “strap line” of the book is that “Success always starts with failure.” You are a successful author… so what was the failure that set you up for success? I was working on a book before The Undercover Economist… it was going to be a sort of Adrian Mole/Bridget Jones’ Diary-styled fictional comedy, in which the hero was this economist and through the hilarious things that happened to him, all these economic principles would be explained--which is a great idea--but the trouble is that I am not actually funny. Another example would be my first job as a management consultant… and I was a terrible management consultant. I crashed out after a few months. Much better that, than to stick with the job for two or three years-- a lot of people say you have got to do that to “show your commitment.” Taking the job was a mistake--why would I need to show my commitment to a mistake? Better to realise you made a mistake, stop and do something else, which I did. That idea that “failure breeds success” is central to most entrepreneurs. Do you think we need more of it in the UK? I think that the real problem is not failure rates in business; the problem is failure rates in politics. We need a much higher failure rate in politics. What actually happens is politicians--and this is true of all political parties--have got some project and they’ll say, “Right, we are going to do this thing,” and it is quite likely that idea is a bad idea--because most ideas fail; the world is complicated and while I don’t have the numbers for this, most ideas are, as it turns out, not good ideas. But they never collect the data, or whatever it is they need to measure, to find out where their idea is failing. So they have this bad idea, roll this bad idea out and the bad idea sticks, costs the country hundreds, millions, or billions of pounds, and then the bad idea is finally reversed by the next party on purely ideological grounds and you never find out whether it really worked or not. So we have this very, very low willingness to collect the data that would be necessary to demonstrate failure, which is the bit we actually need. To give a brief example: Ken Livingstone, as Mayor of London, came along and introduced these long, bendy buses. Boris Johnson came along and said, “If you elect me, I am going to get rid of those big bendy buses and replace them with double-decker buses.” He was elected and he did it, so… which one of them is right? I don’t know. I mean, isn’t that crazy? I know democracy is a wonderful thing and we voted for Ken Livingstone and we voted for Boris Johnson, but it would be nice to actually have the data on passenger injury rates, how quickly people can get on and off these buses, whether disabled people are using these buses… the sort of basic evidence you would want to collect. Based on that, are you a supporter of David Cameron’s “Big Society”, which in a sense favours local experimentation over central government planning? Well, I have some sympathy for the idea of local experimentation, but what worries me is that we have to have some mechanism that is going to tell you what is working and what is not--and there is no proposal for that. Cameron’s Tories seem to have the view that ‘if it is local then it will work.’ In my book, I have all kinds of interesting case studies of situations where localism really would have worked incredibly well, as in, say, the US Army in Iraq. But I have also got examples of where localism did not work well at all--such as a corruption-fighting drive in Indonesia. Is the new book, Adapt, your movement away from economic rationalist to management guru? Are you going to cast your eye over bigger problems? The two changes in Adapt are that I have tried to start with the problem, rather than saying, “I have got a hammer--I’m going to look for a nail.” I started with a nail and said, “Ok, look, I need to get this hammered in.” So I have started with the problem and then looked anywhere for solutions. And the second thing is that I have tried to do is write with more of a narrative. This is not a Malcolm Gladwell book, but I really admire the way that people like Gladwell get quite complex ideas across because they get you interested in the story; that is something that I have tried to do more of here. I am not too worried about it, because I know that I am never going to turn into Malcolm Gladwell--I am always going to be Tim Harford--but it doesn’t hurt to nudge in a certain direction. On Amazon, we recommend new book ideas to people: “If you like Tim Harford you may like…”, but what does Tim Harford also like? I read a lot of books, mostly non-fiction and in two categories: people who I think write a lot better than I do, and people who think about economics more deeply than I do. In the first category I am reading people like Michael Lewis, Kathryn Schulz (I loved her first book, Being Wrong), Malcolm Gladwell and Alain de Botton. In the second category, I read lots of technical economics books, but I enjoy Steven Landsburg, Edward Glaeser (who has a book out now which looks good), Bill Easterly… I don’t necessarily agree with all of these people! When I am not reading non-fiction, I am reading comic books or 1980s fantasy authors like Jack Vance.

    Today that number is one percent. What went so wrong? Losing the Signal is a riveting story of a company that toppled global giants before succumbing to the ruthlessly competitive forces of Silicon Valley. This is not a conventional tale of modern business failure by fraud and greed. The rise and fall of BlackBerry reveals the dangerous speed at which innovators race along the information superhighway. With unprecedented access to key players, senior executives, directors and competitors, Losing the Signal unveils the remarkable rise of a company that started above a bagel store in Ontario. At the heart of the story is an unlikely partnership between a visionary engineer, Mike Lazaridis, and an abrasive Harvard Business school grad, Jim Balsillie. Together, they engineered a pioneering pocket email device that became the tool of choice for presidents and CEOs. The partnership enjoyed only a brief moment on top of the world, however. At the very moment BlackBerry was ranked the world's fastest growing company internal feuds and chaotic growth crippled the company as it faced its gravest test: Apple and Google's entry in to mobile phones. Expertly told by acclaimed journalists, Jacquie McNish and Sean Silcoff, this is an entertaining, whirlwind narrative that goes behind the scenes to reveal one of the most compelling business stories of the new century.

    As she sped through the pages, she became enthralled by the intense drama behind the competition to discover the code of life. Even though her high school counselor told her girls didn’t become scientists, she decided she would.Driven by a passion to understand how nature works and to turn discoveries into inventions, she would help to make what the book’s author, James Watson, told her was the most important biological advance since his co-discovery of the structure of DNA. She and her collaborators turned ​a curiosity ​of nature into an invention that will transform the human race: an easy-to-use tool that can edit DNA. Known as CRISPR, it opened a brave new world of medical miracles and moral questions. The development of CRISPR and the race to create vaccines for coronavirus will hasten our transition to the next great innovation revolution. The past half-century has been a digital age, based on the microchip, computer, and internet. Now we are entering a life-science revolution. Children who study digital coding will be joined by those who study genetic code. Should we use our new evolution-hacking powers to make us less susceptible to viruses? What a wonderful boon that would be! And what about preventing depression? Hmmm…Should we allow parents, if they can afford it, to enhance the height or muscles or IQ of their kids? After helping to discover CRISPR, Doudna became a leader in wrestling with these moral issues and, with her collaborator Emmanuelle Charpentier, won the Nobel Prize in 2020.

    The insurance industry’s actuarial tables and the gambler’s roulette wheel both yield to the tools of probability theory. Most situations in life, however, involve a deeper kind of uncertainty, a radical uncertainty for which historical data provide no useful guidance to future outcomes. Radical uncertainty concerns events whose determinants are insufficiently understood for probabilities to be known or forecasting possible. Before President Barack Obama made the fateful decision to send in the Navy Seals, his advisers offered him wildly divergent estimates of the odds that Osama bin Laden would be in the Abbottabad compound. In 2000, no one—not least Steve Jobs—knew what a smartphone was; how could anyone have predicted how many would be sold in 2020? And financial advisers who confidently provide the information required in the standard retirement planning package—what will interest rates, the cost of living, and your state of health be in 2050?—demonstrate only that their advice is worthless.The limits of certainty demonstrate the power of human judgment over artificial intelligence. In most critical decisions there can be no forecasts or probability distributions on which we might sensibly rely. Instead of inventing numbers to fill the gaps in our knowledge, we should adopt business, political, and personal strategies that will be robust to alternative futures and resilient to unpredictable events. Within the security of such a robust and resilient reference narrative, uncertainty can be embraced, because it is the source of creativity, excitement, and profit.

    This entertaining guide builds on scores of case studies taken from business, sports, the movies, politics, and gambling. It outlines the basics of good strategy making and then shows how you can apply them in any area of your life.