The 2-tailed sign test was used to test whether median current inventory levels were different from median inventory levels that mills reported would be necessary absent STHRs. Similarly, on 5-point Likert scale questions, we used a 2-tailed sign test to determine whether the median response was different from neutral (x = 3).
Pulp mills rated increasing the amount of timber on the market as the most important reason for making direct stumpage purchases, small sawmills rated reducing delivered timber cost as most important, and large sawmills rated greater control over wood supply and overcoming STHRs as most important, although differences in rankings between mill types were not statistically significant (P > 0.05).
Respondents suggested that STHRs caused them to hold high inventory levels, particularly during the first and second quarters (Fig.
Fifty-two percent of mills suggested that weather was the primary cause of unutilized logging capacity in Wisconsin, whereas 33 percent blamed STHRs. Fewer than 5 percent of respondents suggested that mill quotas were the primary cause of unutilized logging capacity.
Overall, 70 percent of responding mills had adjusted their procurement practices because of STHRs, including all responding pulp mills, 66 percent of large sawmills, and 63 percent of small sawmills.
The largest cost associated with STHRs for pulp mills and small sawmills resulted from increased inventory (Table 3).
The total cost of STHRs to Wisconsin's forest industry was estimated to be $57.6 million.
Respondents were asked their opinions of STHRs as they are currently applied.
Pulp mills disagreed with the notion that STHRs are a cost-effective method of protecting the environment (P < 0.01); the response from sawmills was not statistically different from neutral (P > 0.05; Table 5).
STHRs, such as those motivated by oak wilt, also come into effect during the second quarter, which restricts timber supply during this period.
Weather and STHRs not only affect inventory levels, but also logging capacity utilization (Conrad et al.
Small sawmills reported the highest per-ton costs because of STHRs. The higher per-ton costs may be due to the narrow range of product specifications and higher delivered prices paid for raw material.