What is the author's tone in The Theory of the Leisure Class by Thorstein Veblen?

The tone of the book tends to be subjective even though it was written as an academic work. The book is based on the views of the author. It is written from his own observations and thoughts. There is no research and no cited sources in the book. This is a departure from the usual academic works, which are the result of research. The only citations are forms of poetry or things like that and they include nothing that is citable.