Three main alternatives are generally presented to Puerto Rican voters in status plebiscites: full independence, maintenance or enhancement of commonwealth status, and full statehood into the American Union. The exact expectations for each of these status formulas are a matter of debate by a given position's adherents and detractors. Puerto Ricans have proposed positions that modify the alternatives above, such as (a) indemnified independence with phased-out US subsidy, (b) expanded political but not fiscal autonomy, and (c) statehood with a gradual phasing out of federal tax exemption. Most experts downplay the importance of all recent plebiscites. For example, Roberto Barreto wrote in the Marxist International Socialist Review that "all the recent plebiscite proposals have been colonial ones, leaving the final decision in the hands of Congress. By defining the plebiscite as 'non-binding,' the electoral exercise, far from being an act of self-determination, turns into a mere survey. These plebiscites are essentially opinion polls to be considered or ignored by the body that reserves for itself all decision-making powers, the U.S. Congress."