SHANGHAI — Leave it to other countries to soar and swoon in their quarterly economic performance. China prefers a steady pace, at least in its officially reported data.

On Monday, the country announced that its economy had expanded 6.9 percent in the second quarter, unchanged from the year-on-year growth rate in the first quarter.

Powering the Chinese economy were many of the familiar sectors: brisk construction of apartment buildings; strong retail sales, especially online; and rising government deficit spending on infrastructure, including new highways and high-speed rail lines. Much of the new infrastructure is in the sparsely inhabited western deserts, where its short-term economic usefulness may be limited. But President Xi Jinping has a strategic vision, the “One Belt, One Road” plan, to link the economies of Asia, the Middle East, and much of Europe and eastern Africa to the Chinese economy.

What keeps the growth rate of the Chinese economy so smooth? Accounting sleight of hand may play some role. Studies over the years have found that China’s national statisticians appear to overstate growth during periods of economic weakness and understate growth when the economy is booming. A series of recent scandals, particularly in China’s northeast, have also indicated that local officials may overreport economic activity to Beijing when local industries like coal mining and steel production run into difficulty.