Britain's productivity just posted its strongest gains in years, offering a rare positive signal for an economy that's spent most of the past decade stagnating, according to new Bloomberg analysis.

Productivity growth - output per hour worked - is the single most important long-term driver of living standards. The UK has been stuck in a productivity crisis since the 2008 financial crisis, with growth rates that would embarrass most developed economies.

If this surge is real and sustained, it changes the entire trajectory for British growth. Higher productivity means companies can afford to pay higher wages without triggering inflation. It means stronger corporate earnings. It means the Bank of England has more room to cut rates without overheating the economy.

But - and this is critical - one quarter doesn't make a trend. UK productivity data has a history of false dawns. We need to see this sustained over multiple quarters before declaring victory.

The key questions: What's driving it? If it's cyclical factors like businesses finally investing after years of Brexit uncertainty, that's positive. If it's just statistical noise or one-off factors, it means nothing.

Sector breakdowns matter. If productivity gains are concentrated in a few industries like finance or tech, that's less meaningful than broad-based improvement across manufacturing and services.

For investors, UK equities have been undervalued relative to US markets for years, partly due to productivity concerns. If this productivity surge proves durable, British stocks could finally catch a bid.

But verify the methodology first. Productivity statistics are notoriously subject to revision. What looks like a surge today might be revised down to mediocre growth six months from now.