Economies of scale means that output increases faster than input. Here scale refers to large production batches caused by the expansion of production capacity. Here economies refers to cost saving, benefit improvement or increasing return.
According to the above definition, which of the followings does not belong to economies of scale?
A factory had an annual output of 5 million tons of steel, with 100 million capital and 5000 employees involved. Under the condition of unchanged technical level, the investment doubled, and the annual output of steel was 10 million tons.