If earth began to shrink, but its mass remained the same, what would happen to the value of g on earth's surface?

The estimation of g on the surface of the earth relies upon mass and range, truth be told, g = GM/R^2 where G is the newton's gravitational constants, M is the mass of the earth and R the range . Should there be any occassion that would cause R to be diminished, the estimation of g would increment as the opposite square of R on the fact that R is divided, g would be 4 times the original value