Stories about the 2012 presidential election have long had an economic component. Boiled down, they’ve said this: If the economy holds together, if the nascent recovery does not get derailed by some unexpected event — a fiscal contagion that begins in Europe and then spreads to America has long been among the top examples — then President Barack Obama’s path to re-election will be a whole lot smoother.

But if some economic calamity upends the financial apple cart, well, then the election might just be up for grabs. Or could even become former Massachusetts Gov. Mitt Romney’s to lose.

Anyone who has been paying even a bit of attention knows this well. That’s the easy part. What separates the professional prognosticators from the armchair pundits, though, is being able to discern what economic factors will really matter come Nov. 6.

Will a European crisis — perhaps prompted by Greece leaving the euro zone — spur a global downturn? Or might the more important factor be closer to home — literally? There were recent signs that our nation’s housing market may finally be showing signs of getting back on track. How much will this continue?

We’ve written recently in this space about the unemployment rate and its likely impact on the vote. The perception, we argued, matters much more than some magic number, some political over-under.

Same too with markets in general — the Dow and Nasdaq, of course, but also gold and gas, bread and houses, the Facebook IPO.

The equation, ever-changing, is always fascinating.

— The Republican of Springfield

(Mass.)