That book for free thing contains this:
The type of economics that I address in this thread and
chapter is what is described as macroeconomics. This is
that part of economics that deals with the economies of
countries and governments. It also addresses issues such
as government income and spending, and so tax, as well as
the national debt, the role of central banks, inflation and
the balance of trade.
It is an aspect of economics that, despite its importance,
engages only a very small part of the economics profession.
The vast majority of economists deal with microeconomics.
That part of economics deals with the behaviour of
individuals, companies and markets.
Economists like microeconomics because it can be used to
construct deeply theoretical, largely mathematical, models
of behaviour that, if truth be told, tell us very little at all
about how real people, companies or markets behave. That
is because of the simplifying assumptions that too many
economists use in the course of their work.
The usual criticism is that macroeconomics is plagued with vast mathematical models which assume much and explain little while microeconomics is at least rooted in a certain observation of actual human behaviour.
As the best waiter might say, ‘Enjoy’.
Well, yes, the book therefore being about as useful as the average waiter’s ruminations upon economics.