We have conducted parametric economic studies for inertial confinement fusion (ICF) electric power plants using an economic model to estimate the cost of electricity. We found that the economy of scale of the reactor is an important factor in determining the combination of target gain, driver efficiency, and electric conversion efficiency required for an economically competitive system. A strong economy of scale allows a significant reduction in these performance parameters for a given cost of electricity. The degree of reduction is dependent, however, on the maximum achievable chamber pulse rate.