Philip K. Dick's novel about androids, a mood modulator and an empathy test

If anyone remembers one of Philip K. Dick's most popular novels, the one on which "Blade Runner" is based. The action is set in 2021, after a world war that has wrecked the whole earth; part of humanity has emigrated into space, while the rest have stayed behind to suffer the consequences of radiation. Here a device has been invented that lets one choose any mood one likes, the Penfield mood organ, into which one enters a code denoting the owner's disposition for the day: businesslike, or suited to watching television, professional or a sense of superiority. As helpers, a species of android has been created, almost indistinguishable from living people, save for the ability of cells to divide. When the androids begin to flee the off-world colonies in order to win rights on earth, they are tracked down and killed. But how is one to tell an android from a human being? In the USSR a test for empathy is being developed, based on a feeling that is beyond the reach of artificially bred people. A good book. True to life