Economic efficiency of multi-product structure: the evidence from Korean housebuilding firms

The Korean housebuilding industry has been subject to structural changes since the 1980s. One of the key features is that housebuilding firms have become diversified into a range of businesses and as a result display multi-product structure. This paper examines the efficiency of the multi-product structure of Korean housebuilding firms. For the analysis, translog cost functions were estimated using data for 201 building firms for the 3 years 1993–1995. The empirical results indicate that medium-size building firms enjoy increasing returns to scale, whereas large firms experience constant returns to scale. Korean building firms exhibit significant economies of scope in their diversification activities. Large firms have the greatest economies of scope. These results are consistent with cost efficiency for the multi-product structure of Korean housebuilding firms. The estimated optimum scale suggests that many large firms should expand only through diversification.