The present invention (a) provides, at low cost, a water absorbing agent (i) that has a suppressed amount of generated dust and a suppressed amount of dust that increases over time and (ii) that also has a high absorption capacity without load, a high absorption capacity under load, a high vertical diffusion absorbency under load, and a high absorbency in a short period of time, and (b) also provides a method for evaluating, in a short period of time, an amount of dust that increases over time. A particulate water absorbing agent of the present invention includes: a surface crosslinked polyacrylic acid (salt)-based water absorbent resin as a main component; a hydrophilic polymer compound; and a stabilizing agent.