10. Economic valuation of crop pollination by honey bees

Several methods have been proposed for the economic valuation of crop pollination by honey bees and wild insects. This value has been defined as the cost to replace pollination provided by honey bees or wild insects with other sources (e.g. hand pollination) (Allsopp et al., 2008), the income of crop production attributable to pollination (Morse and Calderone, 2000; Gallai et al., 2009), the net income (income - costs) of crop production attributable to pollination (Olschewski et al., 2006; Veddeler et al., 2008; Winfree et al., 2011), or a consumer surplus approach (Southwick and Southwick, 1992). Considering the studies using these methods, some focused on the effects of the total depletion of biotic pollination; however, typical management decisions only produce partial changes in biotic pollination (Fisher et al., 2008). Therefore, marginal values are most useful when designing management strategies. Here we describe briefly how to quantify the contribution of adding hives of honey bees to the value of crop production at the local scale, using the net income method (Olschewski et al., 2006; Veddeler et al., 2008; Winfree et al., 2011). The critical variables are the increase in yield realized by the addition of X hives (equation02).

Valuation methods apply differently at different scales such as global (Gallai et al., 2009), national (Southwick and Southwick, 1992; Morse and Calderone, 2000), regional, subregional, or local. In sections 10.1. and 10.2., we focus on the local scale because this is the level at which management decisions are applied, i.e., the optimal density of hives needed for a certain crop species. At regional or larger scales, lower crop yield produced by massive losses of pollinators can generate compensatory increases in cultivated area to maintain crop production (Garibaldi et al., 2011) or increases in market prices of crops (Winfree et al., 2011), and these are treated in sections 10.3.

10.3. Economic valuation at larger scales