In the case of this book, he's proposing a new "theory" (I'm putting it in quotes because it's weaker than a scientific theory, but stronger than the popular us

In the case of this book, he's proposing a new "theory" (I'm putting it in quotes because it's weaker than a scientific theory, but stronger than the popular use of the word), with the most comprehensive and far reaching national-level economic dataset that has existed up to this point (as far as I am aware). In that sense, I feel his work is more concrete than most economic research I've read, and it's several orders of magnitude away from the typical economist op-ed with a single chart, and some cherry-picked data. His predictions for the future are pessimistic, and down the line they will certainly be at least partially verifiable. Only partially, because economies are huge and ghastly things, that we apply numbers to, but don't really have a complete handle on. There are almost always enough extraneous or unaccounted for factors for an opposition group to claim an opposing viewpoint. I think part of the value from Piketty's work is that he tries to account for as much of the data that is integral to his theories as possible (moreso than most economists). Writing this has made me a bit thoughtful, so I'll also take this an an opportunity to go off on a related personal tangent/ramble. Hopefully I don't bore you too much, feel free to ignore. I have always, always, been frustrated with economics. A field that is so divisive, but represents itself as a "science", has always annoyed the hell out of me. However, my academic and professional track has brought me further into economics over time, rather than away. Right now I have a BS and MS in environmental science, and an MPA in energy policy. I'm nearly certain I want to pursue a PhD in the future, and it looks more and more like it will probably be in energy economics. One way I have calmed down my inner turmoil over this is to more frankly assess my economist and scientist sides. Basically, the scientist is in love with raw, pure, data generation, while my inner economist is about using that data to generate a picture (or a graph, so many graphs). Another side to this is that my inner economist constantly wants to generate an interesting narrative and draw out the connections between trends, while my inner scientist tears down those hypotheses or works to find the data points which are not influenced by a "narrative". I've been happy on a lab bench centrifuging, pipetting, and doing PCR in the process of splicing soybean embryos, but I also enjoy sifting through census data and plotting $/kWh trends. Ultimately, I still maintain a distrust of the broad field of economics, but I think the phenomenon we broadly place within it could do with a more thorough explication via more scientific methods.