Yes, but when he says 'Sweden works, Cuba doesn't, therefore free market economies are better' his logic is hard to follow.

Firstly Sweden is more of a social democratic economy than a free market one.

Secondly Cuba's economy has always been strongly limited by trade sanctions from the US.

And finally, what does 'work' mean? Does the US economy, with its vast and increasing inequality, work according to Krugman's definition? Is it hard to imagine that there might be people in Cuba who are better off than people in the US?

The subtext is an obvious and rather naive or unquestioning acceptance of free market exceptionalism compared to the alternatives - when the reality is that in fact free market economies only 'work' in the libertarian sense of increasing inequality, to the point where inequality and autocratic top-down policy are a good effective definition of the political and financial output of a so-called free market.

Free market economies can only work if they're based on an imperial model which steals resources from other countries. Even then they blow up every few years, and they deny most people democratic participation. They're also suicidally bad at long-term planning and prone to outbreaks of corporate banditry and corruption.

That's a strange definition of 'work' - unless you start from the assumption that they're the best of all possible arrangements by definition, and work back from that.