1. A method for predictively encoding a motion vector used in motion compensated prediction of a video sequence consisting of a temporal sequence of frame pictures, the method comprising: a step of determining a motion vector of a target partition in a frame picture of an encoding target in the video sequence; a step of determining a first motion vector predictor candidate that satisfies a first predetermined criterion used in determination of first motion vector predictor candidates, the first motion vector predictor candidate determined from a motion vector or motion vectors of one or more partitions belonging to a left-neighboring region located on a left side of the target partition; a step of determining a second motion vector predictor candidate that satisfies a second predetermined criterion used in determination of second motion vector predictor candidates, the second motion vector predictor candidate determined from a motion vector or motion vectors of one or more partitions belonging to an above-neighboring region located above the target partition; a step of selecting a motion vector predictor and outputting motion vector predictor indication information to specify the selected motion vector predictor, wherein the motion vector predictor is selected based on comparison between one or more motion vector predictor candidates including the first motion vector predictor candidate and the second motion vector predictor candidate, and the motion vector of the target partition; and a step of encoding the motion vector predictor indication information, wherein the left-neighboring region includes a neighboring partition located below and on the left side of the target partition, wherein the above-neighboring region includes a neighboring partition located above and on a right side of the target partition, wherein the above-neighboring region includes a neighboring partition located above and on the left side of the target partition, wherein the step of determining the first motion vector predictor candidate comprises scanning, in an upward direction starting from a bottom of the left-neighboring region, one or more partitions included in the left-neighboring region, and thereby determining, as the first motion vector predictor candidate, a motion vector satisfying the first predetermined criterion used for determination of first motion vector predictor candidates, the first motion vector predictor candidate determined from the motion vector or motion vectors of the one or more partitions belonging to the left-neighboring region, and wherein the step of determining the second motion vector predictor candidate comprises scanning, in a direction from right to left, one or more partitions included in the above-neighboring region, and thereby determining, as the second motion vector predictor candidate, a motion vector satisfying the second predetermined criterion used for determination of second motion vector predictor candidates, from the motion vector or motion vectors of the one or more partitions belonging to the above-neighboring region.