In its fourth edition, <I>Economics Explained</I> continues its announced purpose -- to explain that mysterious thing called economics. But there is a new urgency to the book. It is announced in the first sentence of the introduction: "Just in case the reader-to-be hasn't noticed, disturbing things are going on in the American economy these days." <P> This new edition is about these disturbing things: a trend toward inequality of incomes, the appearance of a new "globalized" capitalism, the "specter" of inflation. As before, Robert Heilbroner and Lester Thurow treat these problems in language that seeks to make clear their causes and treatments. In this straightforward, highly accessible reference, Heilbroner and Thurow -- two of America's most respected and articulate economists -- offer all the economics essential for becoming an effective investor, a savvy business decision maker, or simply an informed member of society.