Thank you for reply.
Yes, it's a pre-chosen fishnet with data, size, shape and alignment. It's a shapefile from another study that I'm trying to replicate, just with new data. I was thinking just to use that, and join the new data from another layer based on spatial location. If it would change anything, I could create my own fishnet, and not steal from the study, but dont know if it would solve the problem of not all cells being represented.
Citation from the study
"A potential challenge to our study is that the DHS surveys are only representative for that location and cannot inform us about nonsampled locations. We present below our method to interpolate measurements between locations. This method must necessarily underestimate variability within locations, and we do not see any obvious source of systematic bias. If so, our imperfect data should attenuate our results, leading to nonsignificant findings...() we interpolate data on wealth levels using a method designed for spatial data in GIS. The “Inverse Distance Weighted” (IDW) method".