And there are gaps in the series, meaning that for some countries there is only one observ ation (so the averages for 2000-2009 for continental Europe and Asia would change if the estimates were based on countries for which two measurements are available). These factors make the estimated averages useful as illustrations. An initial dilemma is whether the subjective indicators should be taken as dependent variables or independent ones, since there are arguments to support either choice (for example, one plausible hypothesis is that, faced with rising dissatisfaction, governments could step up public spending).