There are few things in politics more indecipherable or meaningless to the average Canadian taxpayer than a government announcing a 10-year plan, which is why Prime Minister Mark Carney keeps doing it.

Ten-year plans give the government lots of runway before it has to produce results.

GOLDSTEIN: Ten-year plans are meaningless, which is why Carney loves them Back to video

Carney, for example, may no longer be PM 10 years from now.

In the real world, 10-year government plans are as unreliable as 10-year government deficit projections, because they’re vulnerable to future events over which the government has no knowledge, let alone control.

A government announcing a 10-year economic plan in 2015, for example, had no idea of what the 2020 pandemic would do to the global economy.

Former prime minister Justin Trudeau announced a 10-year, $200-billion-plus plan in 2021 to lower Canada’s industrial greenhouse gas emissions to 40% to 45% below 2005 levels by 2030, which Carney himself dismissed as unachievable in a year-end interview with the CBC.

Ten-year plans also allow governments to post big, speculative and often imaginary numbers in support of the plan, with the public having no way of knowing whether the assumptions underlying them are credible.

For example, promising 125,000 new jobs in a 10-year plan — as Carney did in unveiling his new defence industrial strategy on Tuesday — sounds a lot more impressive than 12,500 new jobs next year, especially since government programs typically take a long time to get going after they’re announced, meaning even speculative job gains are often back-ended to the final years.

In addition to creating 125,000 new jobs over the next 10 years, Carney said his new defence strategy will “increase our defence exports by 50%, raise the share of defence acquisitions awarded to Canadian firms to 70% … grow Canadian defence industry revenues by 240% (and) raise maritime fleet serviceability to 75%, land fleets to 80%, and aerospace fleets to 85%, to bolster Canadian defence.”

But all of this depends on future government decisions and the take-up from the private sector.

While Carney’s 10-year strategy linking defence spending to economic growth — apparently a new concept in government — was praised by the defence sector in principle, it said the real test will be the specifics of implementation, which weren’t provided.

Then there’s Carney’s 10-year plan announced in October to double Canada’s non-U.S. exports with the goal of generating a $300-billion increase in trade.

Sounds great, particularly in the era of tariff-happy U.S. President Donald Trump.

But even if such a strategy, which faces numerous challenges to implement, succeeds to perfection, the reality check is that this would still leave the U.S. as our largest export market by far, given that 75% of all Canadian exports today go to the U.S.

During last year’s federal election, Carney promised to double Canada’s current rate of new residential construction to 500,000 homes per year over the next decade.

But a report by the parliamentary budget office in December said the lead agency the government has created to achieve this goal — Build Canada Homes — is projected to build only 26,000 new housing units, half of them affordable, over the next five years.

Once again, the acid test for Carney’s promise will be take-up from the private sector, because it’s the private sector, not government, that actually builds homes.

It’s all well and good for governments to have long-range plans, but don’t forget that’s all they are — highly speculative projections on a potential future, which may or may not ever happen.

GOLDSTEIN: The massive carbon footprint of Trudeau’s post-political life

GOLDSTEIN: Just admit it, Canada, the EV market has crashed

GOLDSTEIN: New study highlights pay disparity between public, private sectors

© Edmonton Sun