3. Data

We used data of the Ethiopian Annual Agricultural Sample Surveys (AgSS) from 2003 to 2013 conducted by Central Statistical Agency (CSA) of Ethiopia [24]. The major part of the AgSS is the Main ("Meher") <sup>1</sup> season postharvest survey which consists of area and production, land-use, farm management practices, and crop utilization of private peasant holdings. The specific objectives of main season postharvest survey are to estimate the total crop area, volume of crop production, and yield of crops for main agricultural season in Ethiopia. The data covered the entire rural parts of the country except some of the non-sedentary population zones in Ethiopia (i.e., Afar and Somali regional states). The agricultural products data collection in AgSS surveys cover all cereals, pulses, and oilseeds and the most commonly grown vegetables, root crops and permanent (perennial) crops. Holders growing at least one or more of these and/or other crops are enumerated, and data on crop area and yield condition are recorded; hence data on production of these crops are acquired.

For each year, quantities of various crops production were directly computed from the survey data. These values were aggregated to national, regional, and zonal

<sup>1</sup> "Meher" is the local language in Ethiopia to indicate the main agricultural season.



#### Table 1.

Crops identified in our study and their yield may decline in the absence or decline of pollinators (based on [5, 7, 27]).

levels. In order to get the value of each crop production, the volume of each crop production were multiplied by national average price of each crop item per year. The mean annual prices were computed for each crop item from the monthly producers' agricultural prices released by the CSA [25]. The dollar values of production were calculated by using data from the World Bank database [26]. Deflating the values of productions was also important for ease of comparing values across different years. We used information from the World Bank database [26] to correct the prices for inflation by considering 2011 as reference year. For all zones in respective years, the scope of our study is limited to 38 different types of crops (pulses, spices, vegetables, oilseeds, fruits, and cash crops). The detail on the type of crops, the crop pollinators, and the mean pollination dependency ratio of crops is presented in Table 1.

The crop pollination dependency ratio has been calculated based on the dependency ratio of the recently published for crops by [5, 7], and by using the FAO database<sup>2</sup> [27]. The mean value of pollination-driven yield reduction lying between 100 and 90% is 95% (i.e., pollination is reported as "essential"). The mean pollination-driven yield reduction ranging between 40 and 90% is 65% (i.e., pollination is reported as "great"). The mean pollination-driven yield reduction ranging between 10 and 40% is 25% (i.e., pollination is reported as "modest"). The mean pollination-driven yield reduction ranging between 0 and 10% reduction is 5% (i.e., pollination is reported as "little"). Pollination driven that does not show an increase in yields takes a zero dependency ratio [2, 7].
