השוואת שיטות

	Stochastic Frontier Firm Efficiency Analysis	Diversification-Performance Analysis (Rumelt Categories)
תחום	ניהול אסטרטגי	ניהול אסטרטגי
משפחה	Regression model	Process / pipeline
שנת המקור	1977	1974
הוגה השיטה	Dennis Aigner, C. A. Knox Lovell & Peter Schmidt; George Battese & Tim Coelli	Richard P. Rumelt; Krishna Palepu
סוג	Parametric composed-error regression frontier for firm efficiency	Classification-and-comparison pipeline relating diversification type to firm performance
מקור מכונן	Aigner, D., Lovell, C. A. K., & Schmidt, P. (1977). Formulation and estimation of stochastic frontier production function models. Journal of Econometrics, 6(1), 21-37.	Rumelt, R. P. (1974). Strategy, Structure, and Economic Performance. Division of Research, Graduate School of Business Administration, Harvard University. ISBN: 9780875841090
כינויים	SFA Firm Technical Inefficiency, Parametric Production Frontier Estimation, Composed-Error Efficiency Model, Stochastic Frontier Production Function for Firms	Rumelt Diversification Category Analysis, Related vs Unrelated Diversification Analysis, Corporate Diversification Strategy Classification, Diversification Strategy-Performance Linkage
קשורות	3	3
תקציר	Stochastic frontier analysis (SFA) estimates how far a firm falls short of the best attainable output for its inputs while explicitly separating that shortfall from random noise. Aigner, Lovell and Schmidt's 1977 model introduced the defining idea: a production frontier whose error term is the sum of a symmetric, two-sided noise component and a one-sided, nonnegative inefficiency component. Because deviations below the frontier can come either from bad luck and measurement error or from genuine underperformance, SFA models both and recovers a firm-specific technical-efficiency estimate. Battese and Coelli's 1995 panel-data extension let the mean of the inefficiency term depend on firm characteristics, so analysts can simultaneously estimate the frontier and explain why some firms are more inefficient than others.	Diversification-performance analysis asks whether the kind of diversification a firm pursues — staying focused, expanding into related businesses, or building an unrelated conglomerate — is systematically associated with how well the firm performs. The categorical version originates with Rumelt's 1974 Strategy, Structure, and Economic Performance, which classified diversified firms by specialization and relatedness ratios into single-business, dominant-business, related, and unrelated types and found that related diversifiers tended to outperform unrelated ones. Palepu's 1985 study reframed diversification with the continuous Jacquemin-Berry entropy measure, again finding that related diversification was associated with superior profit growth, and showed how the index approach and Rumelt's categorical method can be combined to gain both objectivity and conceptual richness.