Your monitor example is good and real, however due to the shape, it's not clear that it could easily be included fully assembled in the same-sized box.
What I point out the lack of, is assembly where it could already be assembled. So, while you do have to attach a monitor to its base, you don't have to put on a rear panel, even if it snaps on, or do anything else gratuitous. (Added by the manufacturer as an assembly step purely for the Ikea effect.)
In cases where something ships with batteries, it's usually not even included separately, but instead, already fully inserted.
Since products don't add a gratuitous user assembly step, this leads me to believe that the Ikea effect is not real. An AB test would probably clear up whether it is.
The "IKEA Effect" was not designed as such, it was stumbled on accidentally. The reason IKEA furniture is assembly-required is the same reason that your monitor stand comes detached from the monitor: because these companies operate on the principle that their products be flatpackable (minimize shipping dimensions).
Giving a theory a name doesn't mean it's a real effect. I would like to see a blind AB study that shows the effect is actually true and not someone's pet theory but which is actually false. I agree that the theory is nice and has explanatory power. Let's do a controlled study to see if it is real.
I wonder if you would like to see an AB test though? I haven't read any of the other comments in this thread yet, so stop me if you already answered that.
You also missed my point that IKEA effect is not necessarily a "gratuitous" assembly step, just any step(s) at all.
What I point out the lack of, is assembly where it could already be assembled. So, while you do have to attach a monitor to its base, you don't have to put on a rear panel, even if it snaps on, or do anything else gratuitous. (Added by the manufacturer as an assembly step purely for the Ikea effect.)
In cases where something ships with batteries, it's usually not even included separately, but instead, already fully inserted.
Since products don't add a gratuitous user assembly step, this leads me to believe that the Ikea effect is not real. An AB test would probably clear up whether it is.