Well it's a thesis, and (keeping in mind, I'm only a quarter of the way through it) it seems to be spending most of the first section just legitimizing that "Early Buddhism" has any legitimate basis upon which to speak on the subject Economic Philosophy, addressing and ruling out potential objections from the likes of Max Weber.
Many interesting sutta quotations along the way, and whilst it's not yet putting forward a theory as such, the purpose is to show that material and spiritual development may not be merely compatible, but mutually synergistic.
As it is, the main thrust of what's been said to date, in a practical sense, is that it's very important for the lay Buddhist to find appropriate balance between material and spiritual cultivation.
"Having understood name-and-form, which is a product of prolificity,
And which is the root of all malady within and without,
He is released from bondage to the root of all maladies,
That Such-like-one is truly known as 'the one who has understood'." (Snp 3.6)
"Whether I were to preach in brief, Sāriputta, or whether I were to preach in detail, Sāriputta, or whether I were to preach both in brief or in detail, Sāriputta, rare are those who understand." (A I 333, Sāriputtasutta)