Looking more closely at the way people form expectations about the possible outcome of the election in their electoral district I will provide evidence for the first time that strategic voting can be observed and predicted even in PR systems with large districts magnitudes, such as in Portugal. Employing district-level data from 1975-2002 I estimate that a party, who is expected to win no seat, will be strategically deserted on average by about 3 per cent of the voters. This number does systematically vary with the district magnitude of each district and is largest (> 4 per cent) in Portugal’s smallest electoral districts (e.g., Beja and Évora). Nevertheless even in Portugal’s largest electoral district, Lisbon, strategic voting can be observed to have a systematic impact on parties vote shares.
