I am conducting MSA (Metropolitan Statistical Area) level analysis where I am tracking the number of corporate headquarters in the top 50 MSAs from 2000 to 2014. I am looking for a shapefile like this for both 2000 and 2014 (or close to 2000 and 2014). Has anyone used such shapefiles and if so, did you find them online or have to construct them on your own? If there is a shapefile for all corporate headquarters in the US for 2000 and 2014, I can do select by location with a MSA shapefile. Or if I can get a list of corporate headquarters by MSA for 2000 and 2014, I can just join the data file to the MSA shapefile.