This is Chapter 4 of my PhD thesis Understanding the World Wool Market: Trade, Productivity and Grower Incomes, UWA, 2006. The full thesis is available as Discussion Papers 06.19 to 06.24. This chapter has three broad aims: (i) to describe the sources and methods used to construct the WOOLGEM database; (ii) to summarise the resulting database to aid in the interpretation of simulation results; and (iii) to describe the sources and rationale underlying the parameters used to calibrate the behavioural equations in the WOOLGEM model.