Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Still a mistery...

Helpman, his name notwithstanding, doesn't help much in understanding "the mystery". Maybe the title is far too ambitious, maybe it's because of his often convoluted writing, maybe because the most important recent evolutions in growth theory seem not to have been thoroughly digested by the author, maybe because there's little about the politics of economic growth. In fact, the part on governance and institutions in particular is less than clear. The first chapters are better, though: clear and comprehensive. But that is not enough to make of this book a classic.