CHAPTER III
 EMPIRICAL MODEL


 Introduction


 This chapter presents the empirical model for the Gulf of Mexico

Reef Fish Fishery to be utilized in simulating the effects of various

management alternatives. The first section of this chapter deals with

the specification and estimation of the regional catch equations. The

second section contains the regional demand equations facing producers.

 Before proceeding with the specification and estimation of the

various empirical relationships, a brief discussion concerning the

nature and type of data employed in this study is in order. As with

many fisheries, data on the GMRFF are extremely limited. Primary data

at the firm level are almost non-existent. While some data of this type

could be collected for perhaps one or two years, this would not be suf-

ficient given the long-run nature of this study. Furthermore, virtually

no consistent continuous set of biological data on resource stock sizes

suitable for econometric analysis exist. Such data could be collected,

but only at extremely high costs in terms of both time and dollars.

 The major source of data used in this study is Fishery Statistics

 of the United States (U.S. NMFS, 1957-1975). The data used thus cor-

 respond to aggregate cross-section time series observations on states

 participating in the GMRFF for the years 1957 to 1975 inclusive

 (Appendix B). Because of the aggregate nature of these data, the


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