When stagflation began to appear in the US economy in the late 1960s, economists and policymakers were perplexed because they had never seen and at the same time.

high inflation rates; high unemployment rates

Explanation:

Generally in economics there is inverse relationship between inflation and unemployment, if inflation goes up , unemployment goes down and vice verse. But in stagflation situation  economy faces both issues high inflation, high unemployment with stagnant GDP growth. There may be other reasons but one of main reason is printing of money by central bank with fixed supply increases inflation and unemployment at same time.

the answer is a wheel

permafrost layer, it exists beneath a layer of soil, rock or sediment.