Using lapply with changing arguments

R textbooks continue to promote the use of lapply instead of loops. This is easy even for functions with arguments like

lapply(somelist, f, a=1, b=2) 

but what if the arguments change depending on the list element? Assume my somelist consists of:

somelist$USA
somelist$Europe
somelist$Switzerland

plus there is anotherlist with the same regions and I want use lapply with these changing arguments? This could be useful when f was a ratio calculation for example.

lapply(somelist, f, a= somelist$USA, b=anotherlist$USA) 

Is there are way except for a loop to run through these regions efficiently?

EDIT: my problem seems to be that I tried to use a previously written function without indexes...

ratio <-function(a,b){
z<-(b-a)/a
return(z)
}

which led to

lapply(data,ratio,names(data))

which does not work. Maybe others can also learn from this mistake.