Beijing's lingering smog not only makes me sneeze like clockwork but also casts a haze over my otherwise longstanding victory in a debate with my husband - a sustained dispute over whether his native Shanghai or the country's capital is the best nest for our family to roost in.

The debate began soon after my hubby moved to Beijing in 2002.

The conclusion to this tale of two cities is subjective. It's based more on personality and individual life trajectory than on absolute or universal metrics.

I'm not a Shanghai native, but I spent four years attending university there before moving to Beijing, where I find we can afford a happier and more relaxed life.

Beijing boasts an allure for virtually anyone - aside, perhaps, from Shanghai natives.

There's a well-known joke: Shanghai is the only real city in China - but only in a Shanghai native's eyes.

"Beijing is such a huge village," my husband grunts.

This statement is often the prelude to a lamenting exposition about Beijing's inferiority to his hometown. The ensuing chapters are about the capital's comparative dirtiness - the ubiquitous loogies speckling the sidewalks are the worst - clogged traffic and foul odors that pervade the subways.

Rather than refute these points, I abridge his critique by highlighting Beijing's bright side. This used to be easy because I know both cities as well as I know my spouse.

I know he enjoys Beijing's diversity.

So, I spout the litany of historical sites and mountainous suburbs that make weekends fun.

The prologue to my defense of the city used to be weather. I know he prefers Beijing's relatively arid climate to Shanghai's muggy and sweltering summers; chilly and rainy winters; and year-round cloud cover.

That used to push the final tally in my favor.

"All right," he would say, sighing. "At least Beijing has more sunny days."

And with that point, I'd win the debate - or at least a few days' reprieve.

But that has changed since Beijing has become synonymous with smog - a place where people start their days by checking the PM2.5 before the traditional weather forecast.

The hazy skies mean I often can't stay clear of the debate with my husband for even one day.

The times I'm least likely to have to deal with the discussion is when strong nighttime winds produce blue morning skies.

Otherwise, the back-and-forth now ends sometimes with me going to-and-fro with myself over the question: As the mother of a 2-year-old, should we move to Shanghai?

The murkier Beijing's skies get, the clearer the answer becomes.

Contact the writer at linshujuan@chinadaily.com.cn.

(China Daily 11/03/2013 page3)