below the 2019–21 average could indicate a strong conflict effect, although a more modest decline of the summer crop area in 2022 (by 0.74 million ha from the pre-war average) and an increase (by 0.33 million ha) in 2023 suggest that, before drawing conclusions, other factors must be considered and controlled for.

Table 3 illustrates the need for difference-in-differences analysis of conflict effects by presenting the area cultivated for summer crops (panel A), winter crops (panel B), and fallow land (panel C) overall and separately for VCs that were or were not affected by the conflict, based on official data, or that experienced crop damage, based on satellite imagery from the 2023 or 2022 planting and growing seasons. While the first line in each panel replicates the national figures, the subsequent lines point toward clear differences across villages by conflict incidence. In VCs with war-related field damage based on remotely sensed data, the summer crop area was 880 ha (31%) or 871 ha (26%) below the pre-war mean in 2022 or 2023, respectively (panel A). In VCs without field damage, the summer crop area in 2022 and 2023 was 16.6 ha (or 1.0%) below or 108.2 ha (or 7.0%) above the pre-war mean, respectively. Differences for VCs where conflict was measured using open-source data rather than satellite imagery are of similar magnitude.

Panel B in table 3 points toward similarly large effects for winter crop area, with a reduction of 1,028 ha (or 45%) for VCs where crops were damaged, based on remotely sensed data in 2023 (788 ha for VCs with conflict based on open-source data), compared to 120-125 ha for those not affected by the conflict. As 2022 winter crops were planted before the Russian invasion in February 2022, it is not surprising that even for VCs that were affected by the conflict during the growing season for 2022 winter crops, the mean winter crop area was reduced by 228 ha only if satellite imagery is used, or by 106 ha if open-source conflict data are used.

<mark>Weather affects agricultural production in ways that are unrelated to conflict. To account for weather variation, we generate data on precipitation and minimum or maximum temperature from the US National Center for Environmental Prediction Global Forecast System, which produces weather forecasts every six hours. For the 2019–23 growing seasons, we use the first six-hour interval of each forecast, extracted u</mark> sing Google Earth Engine scripts <mark>, as a “nowcast” to derive daily aggregated values</mark> at the rayon level.

<mark>The temperature data are then converted into growing degree days (GDDs), using</mark> daily values of _Tmin_ and _Tmax_ <mark>with a sinusoidal distribution as suggested by d'Agostino and Schlenker (2016).</mark> In line with the literature, we then compute the cumulative GDDs as the number of hours with temperatures above 5̊° C (41° F) for summer crops (see figure 4) and 0° C (32° F) for winter crops (see figure 6). To complement GDDs, we also compute cumulative precipitation in each year for summer crops (figure 5) and winter crops (figure 7). The summer growing season in 2019 was very warm; in 2022, rainfall after mid-May remained below average; and 2023 had ample rain in the spring but a dry summer. For winter crops, 2023 combined 9