Figure 2  Gross public debt in the euro-area countries in 2010 (as a percentage of GDP)  60  30  30  0  0 E ur o  G re ec  ar ea  60  e  90  Ita ly  90  Au st ria Fr an ce G er m an y P or tu ga l Ire la nd Be lg iu m  120  M al ta  120  S pa in C yp ru N s et he rla nd s  150  E st on Lu ia xe m bo ur g Sl ov en ia Sl ov ak ia Fi nl an d  150  Source: European Commission, Autumn Forecasts (2011).
If we want to save oil, for example, it is useless to appeal to the conscience of citizens, it is enough to increase the price of petrol and diesel; if we want to protect the environment from petty pollution by the public we can only educate citizens to be conscientious.