To select high-quality government bonds we thus want to compare the state of the economy across countries. There are some challenges to gaining timely data on the state of the economy, though.
The official data series for economic growth is GDP, a comprehensive measure of economic activity. The drawback of this series is that, for most markets, it is updated only quarterly, with a publication lag of at least a month. Moreover, the data is prone to substantial revisions. This means that a bond selection process in early July would either use first-quarter data, showing which economies were growing strongly four to six months previously, or would need to be delayed by a few weeks until the publication of the first estimates of second-quarter growth – and maybe even longer as these numbers might be revised later on.
Fortunately, many macroeconomic data series are released more frequently and with a shorter publication lag than GDP. However, these indicators typically relate only to specific parts of the economy. To get the full picture of the overall economy, it is necessary to combine several data series.
For this we use nowcasts, daily estimates of current growth based on a wide variety of data series. In early July, many data series give information about May, and some already for June; survey data can shed some light on what could be expected in July. This is an advantage compared to the traditional GDP numbers: by combining data series that are updated faster and more frequently, one can create a comprehensive measure of activity that leads the latest published GDP data by up to several months.