A dispersing agent useful in a suspension polymerization process, the dispersing agent comprising: a polyvinyl alcohol having: a degree of hydrolysis in the range from 60 to 80 mol%; an absorbance of not less than 0.3 measured at a wavelength of 320 nm with respect to a 0.1 wt% aqueous solution of the polyvinyl alcohol; a block index of remaining ester groups in the range from 0.4 to 0.5; and a cloud point in the range from 35°C to 50°C measured with respect to a 1 wt% aqueous solution of the polyvinyl alcohol, wherein: the degree of hydrolysis is measured using titration; the absorbance is measured with respect to a 0.1 wt% aqueous solution of the dispersing agent using an Evolution 600 UV-Vis Spectrophotometer, available from Thermo Fisher, Pittsburgh, PA, USA; and the block index is the value obtained from the intensity ratio of peaks based on methylene carbon portions found within the range of 38 to 49 ppm in measurement of 13 C-NMR spectrum measured using 3-(trimethylsilyl)propionic-2,2,3,3-d4acid sodium salt as an internal standard material [chemical shift of (OH, OH) dyad=43.5-46 ppm, chemical shift of (OH, OR) dyad=41-43.5 ppm, and chemical shift of (OR, OR) dyad=38-40.5 ppm] according to equation: η = OH, OR / 2 OH OR wherein (OH, OR), and are calculated by molar fraction respectively, and denotes the molar fraction of hydroxyl group calculated from integral ratio in 13 C-NMR and denotes the molar fraction of acetoxy group at that time; and the cloud point is measured via visual determination of a 1 wt% solution of the dispersing agent in water while heating. a polyvinyl alcohol having: a degree of hydrolysis in the range from 60 to 80 mol%; an absorbance of not less than 0.3 measured at a wavelength of 320 nm with respect to a 0.1 wt% aqueous solution of the polyvinyl alcohol; a block index of remaining ester groups in the range from 0.4 to 0.5; and a cloud point in the range from 35°C to 50°C measured with respect to a 1 wt% aqueous solution of the polyvinyl alcohol, a degree of hydrolysis in the range from 60 to 80 mol%; an absorbance of not less than 0.3 measured at a wavelength of 320 nm with respect to a 0.1 wt% aqueous solution of the polyvinyl alcohol; a block index of remaining ester groups in the range from 0.4 to 0.5; and a cloud point in the range from 35°C to 50°C measured with respect to a 1 wt% aqueous solution of the polyvinyl alcohol, wherein: the degree of hydrolysis is measured using titration; the absorbance is measured with respect to a 0.1 wt% aqueous solution of the dispersing agent using an Evolution 600 UV-Vis Spectrophotometer, available from Thermo Fisher, Pittsburgh, PA, USA; and the block index is the value obtained from the intensity ratio of peaks based on methylene carbon portions found within the range of 38 to 49 ppm in measurement of 13 C-NMR spectrum measured using 3-(trimethylsilyl)propionic-2,2,3,3-d4acid sodium salt as an internal standard material [chemical shift of (OH, OH) dyad=43.5-46 ppm, chemical shift of (OH, OR) dyad=41-43.5 ppm, and chemical shift of (OR, OR) dyad=38-40.5 ppm] according to equation: η = OH, OR / 2 OH OR wherein (OH, OR), and are calculated by molar fraction respectively, and denotes the molar fraction of hydroxyl group calculated from integral ratio in 13 C-NMR and denotes the molar fraction of acetoxy group at that time; and the cloud point is measured via visual determination of a 1 wt% solution of the dispersing agent in water while heating. the degree of hydrolysis is measured using titration; the absorbance is measured with respect to a 0.1 wt% aqueous solution of the dispersing agent using an Evolution 600 UV-Vis Spectrophotometer, available from Thermo Fisher, Pittsburgh, PA, USA; and the block index is the value obtained from the intensity ratio of peaks based on methylene carbon portions found within the range of 38 to 49 ppm in measurement of 13 C-NMR spectrum measured using 3-(trimethylsilyl)propionic-2,2,3,3-d4acid sodium salt as an internal standard material [chemical shift of (OH, OH) dyad=43.5-46 ppm, chemical shift of (OH, OR) dyad=41-43.5 ppm, and chemical shift of (OR, OR) dyad=38-40.5 ppm] according to equation: η = OH, OR / 2 OH OR wherein (OH, OR), and are calculated by molar fraction respectively, and denotes the molar fraction of hydroxyl group calculated from integral ratio in 13 C-NMR and denotes the molar fraction of acetoxy group at that time; and the cloud point is measured via visual determination of a 1 wt% solution of the dispersing agent in water while heating. wherein (OH, OR), and are calculated by molar fraction respectively, and denotes the molar fraction of hydroxyl group calculated from integral ratio in 13 C-NMR and denotes the molar fraction of acetoxy group at that time; and the cloud point is measured via visual determination of a 1 wt% solution of the dispersing agent in water while heating.