Solution:Increasing returns to scale.
■ When the sum of exponent excedsone (a +b > 1) in cobb-Douglas production function, it couses increasing returns to scale.
Properties of cobb-Douglas production function
■ Homogeneous of Degree
■ If (a + b) > 1, increasing return to scale (IRS)
■ If (a + b) = 1, constant return to scale (CRS)
■ If (a + b) < 1, decreasing return to scale (DRS)
(a + b) = 1, it is linearly homogeneous of degree one :