The CORE economics curriculum, designed to provide an introduction to economics that reflects economics as it is today rather than as it was decades ago, has won justified praise from John Cassidy. I also think it is brilliant, not just for first year undergraduates but also for interested non-economists. To wet your appetite, read this short account by two of the leading lights behind the project.
Rather than spend the rest of this post singing its praises, I want to ask why first year undergraduate textbooks represent a clear example of market failure. The failure I have in mind is the inability to teach economics as it currently is, rather than as it was decades ago. If you look at the standard first year, Econ 101 textbook, it does contain more modern stuff, but normally in later chapters after presenting the basic models/frameworks which have not changed for 30 years or more. As a result, textbooks tend to be both dull, seemingly irrelevant and much too large. (This is a blanket generalisation and I’m sure there some exceptions.)
Here is my theory, which I will try and explain in plain english rather than with economics jargon. Although the ultimate consumers of textbooks are students, they are chosen by teachers who set the course textbook. So why are Econ 101 teachers not demanding textbooks that are less dull and more up to date?
Suppose someone had written something like the Core material, and a publisher (as publishers do) had sent it out to people currently teaching Econ 101 for comments. The reaction they will have got from a good proportion of Econ 101 teachers would have been ‘that is interesting, but can we include at the start some of the stuff I have taught for the last five years’. They, naturally, do not want to completely rewrite their courses, and I fear in a few cases learn material that is new to them.
The publisher reports back to the author: ‘we cannot publish this as it stands, but if you start with the traditional material then maybe’. It is a market failure because publishers are looking at the current set of Econ 101 teachers, and not those who will one day teach it and would love to have something more up to date. Another force for conservatism is that the big names who dominate the market find it much easier to add new stuff on at the end as extra chapters than rewrite their textbook from scratch.
I could add more, but I have been rude to enough of my colleagues already. Let we add two other specific points about CORE. The first is that it is clearly mainstream: this is not the pluralist text that many heterodox economists would like. That I fear is inevitable: economics is mainly a vocational subject, not a liberal arts subject. (Thats upset a few more.) But I was surprised to see MMT people describe this textbook as not for them. I have, after all, argued that MMT is just standard macro without what I have called the Consensus Assignment.  So I had a look.
In the section on government finances (14.8) we get
“When there is a budget deficit, this means the government must borrow to cover the gap between its revenue and its expenditure. The government borrows by selling bonds.”
This is not correct, and nor does it follow modern macro.  There we write the government budget constraint to include a term in the change in the stock of high powered money. (If money does not appear, it is because the paper explicitly chooses to work in a moneyless world for simplicity.) In short, the government can finance the gap between revenue and expenditure by creating money. Ignoring money in this section is obviously an oversight, as the discussion in section 10 clearly shows. But it is an oversight that should be corrected. 
That apart, I was already a fan of the macro approach adopted in CORE, because it is a simplified version of the Carlin and Soskice textbook. I like the consistent claims approach as a way of talking about inflation. It emphasises the elementary point that you need both wage and price inflation to get sustained increases in inflation, something monetary policy makers seem to keep forgetting right now.
I like, as some may remember, abandoning the LM curve and explicitly talking about central bank policy. I also like the way that banks are now incorporated as part of the monetary transmission mechanism. If there was a clear manifestation of how outdated (at best, we could also say just plain misleading) most textbooks are, it is their continued use of LM curves and the money multiplier.
I really hope that CORE continues to be successful. It is time we stopped boring and confusing first year undergraduates, and started inspiring them with an understanding of the economic ideas that allow them to address the countless real world economic issues that they will have to face.
 The Consensus Assignment gives monetary policy the goal of macroeconomic stabilisation and fiscal policy the goal of stabilising government debt.
 We can go back to the work inspired by Carl Christ together with Blinder and Solow. I should add that CORE is not alone among textbooks in failing to properly set out the government’s budget constraint.
 Now we all know (and as MMT also clearly states) that there are limits to money financing: too much of it is inflationary. But this should not be internalised by teachers to the extent that money financing is ignored. In particular it gives the impression that to finance a deficit a government has to find someone to lend them money, an incorrect belief that can have very misleading consequences if the government controls its own currency. It is more complicated with independent central banks, but again they are not an excuse to ignore money financing.