Roasia is a developing economy with a large population. its public healthcare and transportation infrastructure is very poor, which creates a bottleneck for industrial development. leading industry experts have been claiming that investment in infrastructure so far has not been sufficient. according to them, there is a pressing need to step up government expenditure on public infrastructure. with the debate heating up, the government proposed a 30 percent increase in infrastructure investment this year. this is also expected to reduce unemployment considerably from the current level of 6 percent. with a 30 percent increase in investment, industry experts predicted that unemployment would decline from 6 to 4 percent in two years' time. however, the unemployment level at the end of two years was even lower at 3 percent. which of the following, if true, can explain this outcome?