Just shortly on Piketty, since his only really notable work was Capital, it's worth noting that most of what he wrote was essentially wrong. Not only were there
methodological issues on his spreadsheets which include transcription errors and incorrect formulae which skew his sources, but MIT graduate Matthew Rognlie took another look at the data and found that almost all of the increasing share of domestic income going to capital was from rising rent on residential real estate. As far as I know, Piketty hasn't addressed these criticisms adequately.
Now. . . On to Chang. Chang is an incredibly poor reflection on Cambridge's economics course; I can't recall a single thing I've read by him that had actual data and analysis, instead he fills up his books with ideological buzzwords and tenuous links. Just take this line from one of
Chang's websites promoting a book of his: "Contrary to what most economists would have you believe, there isnโt just one kind of economics โ Neoclassical economics. In fact there are no less than nine different kinds, or schools, as they are often known. And none of these schools can claim superiority over others and still less monopoly over truth."
This is just utter nonsense on the face of it. Economics is not just guesswork, and certain schools can absolutely take superiority over others. He even includes a
cute little chart, which is
definitionally wrong. Chang is either being stupid or dishonest here (even before we've gotten to the actual economics!) because the schools are simply not delineated like this. It makes no sense.
Classical economics became neoclassical economics
"Neoclassical economics" isn't particularly well-defined anyway
"Schumpeterian" is a branch of growth theory
"Keynesian" is a branch of business cycle theory
"Behavioral" is a branch of microeconomics
All five of those "schools" (at minimum!) are basically mutually consistent. I could write down a New Keynesian business-cycle model with habit formation and a quality ladder, and there you have all five of those "schools." There's just no way you can possibly think schools are "schools" in the hard-and-fast sense. If you want to go by Chang's chart, I'm a I'm a Neoclassical-Keynesian-Schumpeterian with an affliction for Behaviouralism.
On that front, I see the world as basically and broadly, but substantially, mimicking an Arrow-Debreu-Radner equilibrium (read: the laissez-faire world). Maybe 75% of the economy works well along those lines. However, crucially, there are some badly incomplete markets and there is substantially incomplete information on the part of many market participants. Firms have enough market power to make sticky prices and monetary policy important for macro fluctuations. Financial markets and insurance markets are substantially incomplete. Some segments of the labor market badly fail to meet the conditions of Pareto efficient contracts between workers and employers. What does this imply for policy?
Governments can usefully step in to fill the space left by incomplete insurance markets. Governments can usefully step in to design laws that minimize the costly enforcement problems that plague financial markets. Governments can usefully step in to write sensible contract, tort, and property law which aids the public's daily ability to go about their business. Governments can usefully step in to design laws that improve workers' position at the wage bargaining table. Governments can step in with transfer payments to those who are least well off. Monetary policy makers can minimize the ill effects of inflation and rigid prices. Statistical agencies can publish information to curb the problems of imperfect information and costly information processing.
I've read his book Bad Samaritans and it's completely awful. He claims many institutions push conservative theories over liberal-Left theories.
Many institutions push correct theories (
like free trade and globalization as being positive things for the poor and developing countries as well as developed and rich countries) while he and a vocal minority rail against it and use the word "neoliberal" in every other sentence. Chang completely ignores this, going insofar as to claim Hong Kong is the "exception" to his rule. If memory serves, Chang has also occasionally doubted the sloping nature of the demand-supply curves, despite the fact that this has been settled since Smith's
1962 paper. It's akin to doubting the nominal rigidity of wages.
Chang has relentlessly and unapologetically tried to pull economics into the real of politics (more than it already fucking is), and out of the social sciences. He's either dishonest, idiotic or both. Don't even get me started on Twenty-one Things They Didn't Tell You About Capitalism, either. He completely ignores how shitty all economies have become when they tried to achieve autarky and completely ignores endogenous growth models in Bad Samaritans and refuses to acknowledge the technological benefits of trade despite the fact it has been evident since the Middle Ages.
In the end, Chang is a politicised hack. You know what they call alternative medicine which actually works?
Medicine. Similarly, do you know what they call heterodox economics which is coherent and backed by the empirics?
Economics.