It has been argued that improvement in the trade balance can be bullish for a currency due to the increased demand for the currency as a result of the higher overseas demand for the local tradable goods market. Naturally, this has to be offset by the demand for paper that can more than offset the tradable goods sector (eg. US dollar in 2004). The trade argument does work in the yen. Compatibility and timeliness of the data is a problem. First of all, the IMF suggest that the world is running a deficit with itself. The OECD data has a 3 month lag so it significantly degrades the value of trading on this signal in real time.