What could give rise to inflation in the United States?

Financial markets and US households are concerned about a return of inflation in the United States . There is no sign of it at present. What would it take for inflation to actually return in the United States? T hree conditions would have to be met : The excess savings built up by households would have to be consumed and not invested. In other words, there would have to be a shift away from portfolio rebalancing behaviour and a return to transaction money behaviour. This consumption would have to mainly consist of services. An increase in consumption of industrial products could be met by imports without there being inflation. The consumption of services has to be met by domestic production and requires many jobs. The rise in services employment would have to lead to labour market pressures, driving up wages. This would require a return to significant Phillips curve effects, whereas they were still weak in 2018-2019. Yet the institutions and organisation of the US labour market are the same today as in 2019.