How should we manage large database We currently manage a large volume of economic data in Excel in my organisation. All of the data is downloaded from different online databases into Excel spreadsheets (one for each data frequency including annual, monthly, quarterly) - and then one main spreadsheet organises everything and creates tables that we need regularly. By organise, I mean that many of the things we need are simply identities ($Z=X+Y$ where we would have only downloaded data on $X$ and $Y$)

My view is that this could be done much more efficiently in R - where we'd automate the updating of the data and then spit out the tables that we need. But I am not trained at all in data management. 

Would you all recommend a better way of doing this, or are there pitfalls to using R that I am not considering.
As mentioned in another answer, you should consider using a database. In the long run it will make your life easier. 

But, R can help you automate things. You can store excel files in specific folders and/or with specific names (or patterns of names ex. file1_day1, file1_day2 etc) and then create R scripts that process them and produce the report you want.

Since you are using excel files (nothing personal with excel, it is a great program) I am inclined to think that your data will fit in a decent computer running R. In any case, if you end up using R, you should check out data.table package.

Furthermore, R can help you create more complicate reports. Plus, its learning path is not too steep.