That depends on what it spends money on. Infrastructure spending _may_ increase efficiency such that the increased tax burden is less than the efficiency gains

That depends on what it spends money on. Infrastructure spending _may_ increase efficiency such that the increased tax burden is less than the efficiency gains enjoyed by tax payers. In this situation the government has indeed created jobs by expanding the economy. Of course if they pick the wrong projects then efficiency won't rise as fast as the impact of taxation, the economy will shrink, and jobs will be lost. This isn't a special characteristic of governments though - companies (and individuals) can torpedo themselves in the same way (investment ROI is too low), albeit usually on a smaller scale.