Please explain where did this come from and the one thats been highlighted, thanks!

Liquidity-constrained consumers A simple way to capture the idea that some consumers simply consume whatever income they have is to assume that a proportion A (lambda) of the consumers have no wealth and just consume their current labour income. The other consumers hold all the assets and behave in line with the forward-looking consumption the- ory described above. Assuming that both groups have the same labour income per capita, the total labour income of the myopic consumers is M" and the total labour income of the forward-looking consumers is (1 - A) 1". Then we get the total consumption of the myopic consumers: C"I a AY', and of the forward-looking consumers, setting p = r for simplicity, cf= r[(l A) r! +!+ (1 J.) i". 1 + 1" Then total consumption is r 1-). =0" 0:3,!\" 1-1. Y' Y' A. C + +l+r( ) +1+r +1" The factors determining consumption are the same as in the case without myopic consumers but the difference is that current labour income is more important for consumption in this case. Taking the derivative of consumption with respect to current labour income in the above equation we get dc dy' (1-2). 1+r The higher A is, the bigger is the effect of current income on consumption