Reuters details:

Euro zone retail sales unexpectedly fell in December with equal declines in food
and non-food sectors, a sign that consumers in the single currency bloc were reluctant to splurge even in the key holiday period.

The European Union's statistics office Eurostat said on Thursday retail sales in the 16 countries using the euro fell by 0.6 percent month-on-month, for a 0.9 percent year-on-year decline.

Economists polled by Reuters had expected a 0.5 percent month-on-month rise and a 0.2 percent increase year-on-year.

The new data came while European Central Bank policymakers met to decide on interest rates. Economists said they did not expect weak retail sales to prevent the ECB from issuing a warning on inflationary pressures.

The chart below shows the three month change by country and clearly shows the slowdown in aggregate demand within the region.

Source: Eurostat