"The time [sic] of consumerism I advise against is the kind of consumerism that seems to make people unhappy according to the specific research papers I cited."

When writing an essay about achieving happiness, it's not very helpful to define a term as inherently causing happiness or unhappiness, even if you can point to the literature for clarification. You end up with the tautology that "doing X -- which is defined as causing happiness -- makes you happy" or the inverse.

The rest of the essay is a rather nice survey of achieving happiness; I'll be sure to point some friends at it.