Despite all the promises, the benefits have been slow in coming. The main duty-free mall, converted from an old nightclub, is bereft of customers, its shelves of cigarettes and single-malt whiskey standing as still and pristine as museum exhibits. More popular is an adjoining room filled with slot machines and electronic roulette tables, the only type of gambling now permitted in Boten.

Analysts say that much depends on the progress of the China-Laos railway, which has been plagued by funding problems and other delays. Joshua Kurlantzick, a Southeast Asia expert at the Council on Foreign Relations, gave the project a “50 percent chance” of succeeding.

The slow progress makes many Chinese business owners nostalgic for Boten’s glory days, when the lights shone brightly and the town was mobbed by cashed-up tourists.

Zhang Xiangxun, 51, a shopkeeper from Anhui Province who came to Boten six years ago, runs a small grocery on the main street, its shelves heaving with Chinese beer, soap, snacks and fireworks. Business is slow. Mr. Zhang and his wife, Zou Zhonghua, 46, say they earn around 500 renminbi (about $75) per day, barely enough to cover rent and other costs.

But after so many years in Laos, they have decided to wait it out. “The casino’s shut and everything’s very quiet, but we’re still staying,” Mr. Zhang said, tapping cigarette ash into an empty Harbin Beer box.

While the couple are optimistic that Boten’s fortunes, and their own, have finally turned, Mrs. Zou thinks the real solution is much simpler. “If they just opened the casinos again,” she said, “business would increase a thousand percent.”