2017 Measuring Compliance 675 degree of methodological sophistication, allowing for the entry of multiple explanatory factors and for some sensitivity to statistical noise. The residual analysis framework that follows builds on the SERF Index methodology in an attempt to go some way to meeting that demand. B. Conceptual Framework The framework that follows borrows from the analytical toolkit of empirical microeconomics; specifically, those tools that are used to estimate production function frontiers. According to William Greene, “[t]he frontier production function . . . is an extension of the familiar regression model based on the theoretical premise that a production function . . . represents an ideal, the maximum output attainable given a set of inputs.”72 With the setting of this ideal comes the theoretical proviso that all observations fall below it. As such, estimation of the production frontier is generally used as a means to another analytical end: the analysis of technical efficiency. Analysis of technical efficiency in the microeconomic sense refers to the degree to which producers are successful in allocating the inputs they have at their disposal to produce certain outputs in an effort to meet some specified objective. This objective could be to minimize the number and level of inputs to produce a given output (input-approach) or to maximize output with a given number and level of inputs (output-approach). By means of estimating the production function, a measure of efficiency freely emerges since what it corresponds to is the distance between the actual observation and the estimate of the expected ideal. In the case of measuring the extent to which a duty-bearer is meeting or falling short of the level of social welfare it has an obligation to fulfill, the same notion of efficiency can be applied. Each duty-bearer can be treated as a decision-making unit that “produces” the welfare basket under the behavioral assumption that it operates to maximize attainment of the basket (output) given its ability to do so (inputs). Maximum expected attainment at different levels of resource availability can then be predicted and it is these expected values that set the obligation frontier. A signal of compliance or violation, like efficiency, can then be measured as the difference between observed attainment of the welfare basket and the expected level of delivery, or in other words, the level states have an unconditional obligation to provide. 72. William H. Greene, The Econometric Approach to Efficiency Analysis, in The Measurement of Productive Efficiency and Productivity Growth 92, 92 (Harold O. Fried, C.A. Knox Lovell, & Shelton S. Schmidt eds., 2008).