The title of this book isn't a trick question; and the answer you thought of is probably the correct one. The answer, though, explains why it is nearly half a century since a human being set foot on the moon; why Concorde no longer flies across the Atlantic; why the western world is experiencing a "retail apocalypse;" why Britain voted to leave the European Union; why Donald Trump became President of the USA in 2016; and why things are likely to get a lot worse before they get better. The remorseless decline in relative living standards for the majority of people in the western states since 1973 has baffled economists and politicians (of the equally clueless Red and Blue teams). Today they talk about a "productivity puzzle," despite being unable to properly explain what productivity is. In the same way, they talk about economic growth being our salvation despite not knowing how economic growth occurs. In Why Don't Lions Chase Mice, economic and social scientist Tim Watkins explains that without a theory of energy and with a poor and erroneous theory of money, the "experts" and politicians charged with leading us out of the gathering crises - banking and financial collapse, unemployment, under-employment and depression, energy shortages, resource depletion, environmental destruction and climate change - are leading us down a blind alley. Only when we understand the essential role of energy in the economy can we properly understand the stark choices before us. In Why Don't Lions Chase Mice, Tim Watkins explains why neither of the proposed futures on offer - business as usual versus a "green new deal" - is possible. Business as usual fails because Planet Earth cannot withstand the destruction caused by burning even more fossil fuels. Less obviously, though, business as usual fails because we no longer have access to sufficient fossil fuels to carry on as we have been. The alternative of a green new deal, while well-meaning, is not grounded in reality. As Watkins shows, just four percent of our primary energy comes from wind turbines and solar panels. Meanwhile, coal, gas and oil still account for more than 85 percent of our energy mix. The quantity of fossil fuels we would have to burn and the volume of carbon dioxide we would have to release to switch from fossil fuels to renewable energy would create precisely the kind of runaway global warming it is supposed to prevent. In Why Don't Lions Chase Mice, Tim Watkins argues that there are only two possible future directions - a nuclear/hydrogen based revolution (for which we currently lack the technologies or the materials to build them at scale) or some form of de-growth or uncontrolled collapse. His solution is a kind of Brown New Deal in which we harness the fuels and resources available to us in order to prevent collapse and to cushion the blow of de-growth; while continuing to support research and development of viable (i.e. not non-renewable renewable energy-harvesting technologies) energy technologies in order not to entirely close the door on a future energy revolution.