Merge two lists of data, preserving counts between them

Excel 2007, here's what I need to do.

I have 2 lists, both have a text field followed by data. Example

April 2011
Joe Smith 1
Dave Green 2
Alice May 1

and

April 2012
Joe Smith 2
Mark Pierce 3
Dave Green 1

So basically I have month totals of items per person. I want to merge the two sets of data into something like this:

Joe Smith 1 2
Dave Green 2 1
Mark Pierce 0 3
Alice May 1 0

I'm not worried about column headers, I can put those in myself. I want to combine without referencing if possible.
I was fairly sure there is a way to do it, but it escapes me at the moment, and I'd really rather not do it by hand, as I have a lot of data to combine.

Any help would be most appreciated.

Hi,

Where 2011 is in A1:B4 and 2012 is in A7:B10 try this in B14 where the names are in A14:A17.

=IF(ISNA(OFFSET($A$1,MATCH(A14,$A$2:$A$4,0),1)),0,OFFSET($A$1,MATCH(A14,$A$2:$A$4,0),1))&" "&IF(ISNA(OFFSET($A$7,MATCH(A14,$A$8:$A$10,0),1)),0,OFFSET($A$7,MATCH(A14,$A$8:$A$10,0),1))

The ISNA is required or it will return an error if the person does not exist in one of the lists. Copy down.

HTH
Steve