3. Returns to scale Consider the Cobb-Douglas production function, Yt = KANPL-a-b. This production function includes three inputs: capital (Kt), labor (Nt), and land (Lt). a) Under what conditions does the function exhibit decreasing returns to scale in Kt, Nt and Lt individually? b) Show that the function exhibits constant returns to scale in Kt, Nt and Lt jointly. c) Define (lowercase) yt = it ,Kt = Nt Nt It and l, = = . Express yt as a function of kt and Nt It. When does this function exhibit decreasing, constant, and increasing returns to scale