THE JEWS OF HOPE by Martin Gilbert (Viking: $15.95). The title is the most optimistic thing about this depressing book that details the Soviet government's persecution of about 10,000 refuseniks, Jews whose "crime" is their desire to emigrate and who have been refused exit papers. Living in "refusal" means being watched by the police, being arrested on trumped-up charges, being jailed for months without outside contacts, being sent to Siberia and always losing your job. Not having a steady job, of course, is "parasitic" behavior that can result in arrest. Recently, the Soviet government has tightened the screws: Immigration offices have been closed, their hours have been cut, and all applications must be resubmitted every six months. The statistics tell the story: In 1979, 51,330 Jews emigrated; in 1983, the number was 908. Yet, the refuseniks continue to study Hebrew, meet stealthily in small groups and challenge the authorities at every step. Many drop out and give up, others count on public indignation from abroad. The Soviets counter with claims that these would-be emigrants possess top-secret information, and that most of those who have been allowed to emigrate end up in the United States, not in Israel. But what the Soviets are not able to explain is why so many academicians, teachers, scientists and computer experts will risk humiliation, starvation and imprisonment to escape the workers' paradise.