The Econometrics of Cost Modeling: An Overview 105 In its simplest form, a single-output linear cost model is of the form: C = 0 + y Y + i i p i : (4:17) In this case, the parameters to be estimated via regression are coefficients on output ( y ), input prices ( i ), and the constant ( 0 ). On the surface, this particular specification appears to conform to the classic assumptions mentioned earlier, which indicates that the parameters can be estimated via OLS. In upcoming chapters we will see much more complex models that cannot be estimated via this technique but for now we will continue along this vein. At this juncture, some examples are probably in order. Examples: Examining Data--An Illustration of Salient Points The data set RUS97_Basic contains data on the cost of distributing electricity for 707 rural electric cooperatives that distributed electricity in 1997. To get familiar with these data (we will be using them extensively in upcoming chap- ters), the variables of which are defined in Table 4.1, a review of the summary