Available evidence suggests that the preliminary first-quarter GDP estimate released on 25 April will show a small rise from the fourth quarter, although there is downside risk stemming from March’s unusually cold weather.

The Office for National Statistics (ONS) has released data up to February for industrial and construction output and to January for the dominant services sector. If seasonally-adjusted output in each of the sectors were to remain at its latest-available level, GDP would be unchanged on the quarter, with tiny output rises in services and industry offset by a fall in construction.

There are, however, grounds for believing that services output will build on a 0.4% January gain in February / March. First, average retail sales volume in February / March was 1.7% above the January level. The sales numbers are used to measure retail trade output within the index of services. Retail trade has a weight of 6.9% in the index, implying a 0.12% boost to services output in February / March.

Secondly, turnover figures for February released today suggest a further rise in output of other private services industries. The turnover survey is a key input to the index of services but the published numbers – unhelpfully – are in current prices and unadjusted for seasonal and calendar effects. The chart compares services output with a seasonally-adjusted version of the turnover series – the relationship is imperfect but the monthly change in turnover has directionally matched that of output in nine of the last 10 months, and was positive again in February.

A reasonable assumption, based on the above, is that services output rises by 0.4% in February and is unchanged in March. Absent any revision to earlier data, this would imply a 0.3% quarterly gain, in turn suggesting GDP growth of 0.2% (assuming, as before, that industrial and construction output is unchanged between February and March).

This “forecast” is vulnerable to weakness in services industries not covered by the turnover survey (e.g. government and finance) and could also be upset if the ONS has early evidence of a depressing impact from March’s cold weather, although any such effect will unwind in the second quarter.

GDP growth of 0.2% would be little cause for celebration but the recent pattern of revisions suggests that the preliminary number will be raised over time – quarterly GDP changes since the start of 2009 have increased by an average of 0.15 percentage points (i.e. comparing the latest data vintage with preliminary estimates).