Will the real elasticity of substitution ‘in Norwegian dentistry’ please stand up?
利用1993年数据估计挪威私营牙科诊所的超越对数成本函数，分别对独立和联合诊所计算三种不同的要素替代弹性，发现牙医与助手不能简单合并为同质劳动，且替代关系因诊所类型而异。
The non-homothetic production cost structure in Norwegian private dentistry involves more than two factor inputs. Consequently, this paper implements—separately for solo and group practices—three conceptually different measures of factor substitutions to infer the precise nature of input associations using translog cost model estimates based on 1993 data. We calculate own- and cross-price elasticities of factor demands, pairwise elasticities of substitution and their approximate S.E.s. We find that: (1) dentists and dental assistants cannot be consistently aggregated as one homogeneous labour input; (2) input demands are inelastic; (3) the theoretically restrictive Allen–Uzawa and the less restrictive shadow and Morishima elasticities of substitution are not equivalent; (4) dentists and auxiliary dental personnel relate as significant substitutes in solo practices and as significant complements in group practices; (5) ‘supplies’ (e.g., dental materials) in the aggregate are substitutes for the two types of dentistry labour; and (6) there appears to be a wider scope for factor substitutions in group rather than solo practices. Due to inelastic factor demands, opportunities for cost controls are limited despite some tendencies for factor interchange. Finally, future researchers of production costs involving more than two inputs should investigate the less restrictive, alternative measures of factor substitutions. Copyright © 1999 John Wiley & Sons, Ltd.