I like the first one better, simply because it's more parallel. In other words:

This study allowed a [noun] of [something] and the [noun] of [something else]...

Alternatively, the sentence could be structured:

This study [verbed] [something] and [verbed] [something else]...

Using this construct, the sentence would read:

This study analyzed financial results and identified possible causes of negative results...

I think the sentence seems 'tidier' when such parallelism is used, as opposed to:

This study allowed a [noun] of [something] and [verbed] [something else]...

If you really wanted to use that construct (as you did in your second sentence), I'd make it so that the verb was past tense, to match the tense of allowed:

This study allowed an analysis of financial results and identified possible causes of negative results...

Yet another way you could say it would be:

This study allowed an analysis of financial results, identifying possible causes of negative results...

In that last case, identifying possible causes becomes a clarification. Instead of saying that the study had two aims (which is what my previous structures did), it's saying that there was one primary aim of the study (i.e., analyzing results), and that part of this analysis was identifying possible causes of negative results. So, which is better really depends on what you're trying to say.