In recent months, officials with the Bank of Canada (BoC) have repeatedly asserted that Canada’s economy is poised to shift from slackening domestic demand to an increase in exports and a corresponding rise in business investment. And based on the International Monetary Fund’s (IMF) latest “World Economic Outlook,” the Washington, D.C.-based fund appears to be in agreement.

The main hitch, however, is that because the US is Canada’s largest trading partner, much of this economic transition is predicated on a strengthening US economy. Given the fact that the US is in the midst of a government shutdown, and that both political parties are digging in for a protracted budget negotiation, it appears increasingly likely that the shutdown could extend far longer than initially expected.

As we noted last week, for instance, economists at Goldman Sachs project that a shutdown that lasts as long as a month could pare as much as half a point from growth in fourth-quarter gross domestic product (GDP) for the US. Meanwhile, most of the forecasts we’ve seen show the Canadian economy generally taking a hit that’s roughly half the magnitude of the one the US could suffer.

Though the IMF published its outlook in the opening days of the shutdown and did not incorporate a longer-term impasse into its forecast, it did model the effect of an untimely tightening in the US Federal Reserve’s monetary policy in tandem with external shocks, such as a sudden deceleration in growth from other major economies. This downside scenario could lower next year’s GDP growth by a half-point in the US and a quarter-point in Canada.

So political theatrics have introduced considerable uncertainty into near- and medium-term economic forecasts. For now, the BoC forecasts full-year 2013 GDP growth for Canada of 1.8 percent, compared to a 1.6 percent projection by the IMF (down a tenth of a point from its previous estimate), and a consensus of 1.7 percent among Bloomberg’s survey of institutional economists.

Similarly, both the IMF and private-sector economists project the US economy will grow by 1.6 percent in 2013. As such, the Canadian economy is unlikely to experience a boost from US demand this year.

But what about next year? In a recent speech, BoC Deputy Governor Tiff Macklem said the central bank believes the Canadian economy will have to grow at a rate of at least 2.5 percent annualized in order to absorb excess capacity. The BoC’s forecast, which could be revised lower later this month, is for full-year 2014 GDP growth of 2.7 percent.

The BoC’s economic forecasts were last disseminated in mid-July, so that probably accounts for why they seem downright optimistic compared to more recent estimates from other economists. Indeed, the IMF estimates Canada’s economy will grow by 2.2 percent in 2014 (down a tenth of a point from its prior forecast), while institutional economists project growth of 2.3 percent next year. The latter see 2015 as the first full year in which the Canadian economy will grow at a rate–2.6 percent–that exceeds Macklem’s aforementioned threshold.

By contrast, the US economy is expected to grow at a slightly more accelerated pace, though it remains to be seen what the showdown in Washington portends for the coming year. At present, both the IMF and private-sector economists project the US economy will grow by 2.6 percent in 2014.

Although the IMF agrees with the BoC that net exports and business investment will help drive the Canadian economy in the near future, it still says the balance of risks to this outlook are tilted toward the downside, with potentially weaker external demand the primary risk factor. In fact, Canada is still running a considerable trade deficit, with Statistics Canada reporting a moderate widening of the deficit to CAD1.3 billion in August from CAD1.2 billion in July.

That performance fell short of economists’ expectations by a wide margin. The consensus called for the trade deficit to shrink to CAD700 million, while last month’s figure was revised lower, to a deficit of CAD1.2 billion from CAD931 million.

While higher volumes of energy products, metals and minerals helped increase the dollar value of exports by 1.8 percent, to CAD39.8 billion, that result was more than offset by a 2.1 percent rise in imports, to CAD41.1 billion. Over the trailing five-year period, the average monthly trade deficit was CAD566 million, though the latest number is still significantly higher than the low of CAD2.9 billion in July 2012.

The good news is that the dollar value of Canadian exports has exceeded the five-year average of CAD35.9 billion in every month since early 2011. And exports are in a modest uptrend since the middle of last year, with the recent numbers not all that far off from the high of CAD44.5 billion, posted just prior to the onset of the Great Recession.

Still, even a modestly improving trend isn’t yet enough to make a net contribution to Canada’s economic growth. Before that can happen, the US needs to get its fiscal house in order.