5.1 Introduction5.2 Algebraic, Geometric, and Verbal Definitions of the Intrinsic Estimator5.2.1 Algebraic Definition5.2.2 Geometric Representation5.2.3 Verbal Description5.2.4 Computational Tools5.3 Statistical Properties5.3.1 Estimability, Unbiasedness, and Relative Efficiency5.3.2 Asymptotic Properties5.3.3 Implications5.4 Model Validation: Empirical Example5.5 Model Validation: Monte Carlo Simulation Analyses5.5.1 Results for APC Models: True Effects of A, P, and C All Present5.5.1.1 Property of Estimable Constraints5.5.2 Misuse of APC Models: Revisiting a Numerical Example5.6 Interpretation and Use of the Intrinsic EstimatorAppendix 5.1: Proof of Unbiasedness of the IE as an Estimator of the b0 = Pprojb Constrained APC Coefficient VectorAppendix 5.2: Proof of Relative Efficiency of the IE as an Estimator of the b0 = Pprθj b Constrained APC Coefficient VectorAppendix 5.3: IE as a Minimum Norm Quadratic Unbiased Estimator of the b0 = Pprojb Constrained APC Coefficient VectorAppendix 5.4: Interpreting the Intrinsic Estimator, Its Relationship to Other Constrained Estimators in APC Accounting Models, and Limits on Its Empirical ApplicabilityReferences