Index 343 pricing, 168, 231, 232 doctrine, 2­4 for electric utilities, 13­14 Marginal rate of substitution, 210 Marginal rate of technical substitution (MRTS), 9, 117, 297 Market participants, 42 Mark-to-market accounting, 307­308 Mayo single-output quadratic cost model, 166 Member coops, 6 Merchant generators, 53 Microeconomic model, 3 Minimum efficient scale (MES), 23, 114, 115 Modified Accelerated Cost Recovery System (MACRS), 71 Monotonic in output, 110, 201 Morishima elasticities of substitution, 226­227 MRTS, see Marginal rate of technical substitution Multipart tariffs, 251 Multiple product markets, 81 Multiple-output models, 171­173 measures of efficiency for, 175 Multiple-output natural monopoly, 26 Multiproduct cost, 30 Internal revenue code, 82 Interstate highway system, 86 Inverse elasticity rule, 244 Investor-owned utilities (IOUs), 4, 42­44, 135, 194 profit maximization, 5 regulation of, 8­10 IOUs, see Investor-owned utilities IPP, see Independent power producers ISO, see Independent system operators Isoquant, 118 Iterated seemingly unrelated regression, 219 IV approach, see Instrumental variables approach J J test, 186­187 Joint cost allocation, 238 Joint municipal action agencies, 45 K Koyck model, 274 L