Incentive mechanisms for liver lesion control in finishing pigs in the Netherlands.

Liver lesion prevalence in slaughtered finishing pigs in the Netherlands remained relatively high from the mid-1990s until 2004, although sufficient measures existed to control the main cause, an infection with the roundworm Ascaris suum. In July 2004 a new incentive mechanism was installed to induce finishing pig producers to increase control of A. suum infections. This paper compares the effectiveness of two Dutch incentive mechanisms: a collective insurance - in place prior to July 2004 - and a reduction in producer payment for each delivered pig with a liver lesion - in place from July 2004. Liver inspection data of pigs slaughtered in 2003-2006 by a major Dutch slaughter company were analysed with an out-of-sample dynamic forecast test and non-parametric bootstrapping. Results showed that after introduction of the price reduction, mean liver lesion prevalence decreased from 9 to 5%. A reduced liver lesion prevalence ranging from 0 to 46 percentage points was observed on 67% of 1069 farms that delivered both during the insurance and the price reduction. The number of farms with a liver lesion prevalence of 5.0% or less increased from 52 to 68%. The price reduction for each pig with a liver lesion was a more effective incentive mechanism to induce finishing pig producers to control A. suum infections than the collective insurance.

Sequence effects in hedonic judgments of taste stimuli.

Sequential dependencies in taste research may be different from those obtained in other modalities, due to the long interstimulus intervals and the intermediate rinses. In two experiments, subjects judged the pleasantness of 50 aqueous solutions on 150-mm line scales. During data analyses pseudo-sequence effects arose, because data were aggregated over individuals and because the first trials of the experimental sessions deviated from the rest. After correcting for the pseudo-sequence effects, robust regression analyses revealed small but significant sequential dependencies. The current response deviation was positively related to previous response deviations and negatively related to previous subjective, internal representations.