Estimation of LHC and ILC Capabilities for Precision Higgs Boson Coupling Measurements

This paper discusses some aspects of the estimates of Higgs boson coupling sensitivities for LHC and ILC presented at the Snowmass 2013 meeting. I estimate the measurement accuracies underlying the CMS presentation to Snowmass. I present new fits for the ILC capabilities. I present some joints fits to prospective LHC and ILC data that demonstrates the synergy of the High-Luminosity LHC and ILC programs. Contributed to the proceedings of the Snowmass 2013 Community Summer Study.