1. gdp this is god. decomposed into productivity and population. more people more gdp. this is important because sustainability of debt is associated to gdp, if the growth rate is higher than debt interest then the government can comfortably engage in further fiscal expansion through debt. 2. asset prices / profits  remember gdp is productivity and population? stagnant productivity mostly driven by low investment following gfc 07/08 means that there are many marginal and highly leveraged unproductive firms. austerity created a hysteresis effect where low investment reinforced itself over the decade following the crisis. then we leave the eu which is another loss for investment and export oriented firms (more productive).  low wages -> low productivity (mathematical identity) -> low labour costs with ever rising demand for labour -> unprofitable firms still stay afloat but demand more immigrants -> more immigrants -> low wages  in the place of productivity the government incentivised speculation especially in housing. buy to let booms and low rates increase gdp (yes house price inflation makes line go up despite no real activity has occurred).  more immigrants -> low stagnant wages -> low inflation -> low base rate -> cheaper credit -> higher asset prices -> supply of rentals / housing rises -> which would cause real estate to readjust so therefore to increase demand and push the equilibrium back to ever rising rents-> more immigrants  how is all this possible you say? well... the government can somehow maintain a low wage economy while also maintaining profits and ever rising rents? surely there's a point where people can't pay? there indeed is and the solution is more debt, which from 1. requires you guessed it.. more immigrants. taxes are already mostly used for welfare (health, bennies, pensions, etc) debt is used also as spending rises. this debt and spending is used to indirectly subside the unproductive sectors of the economy.
United Kingdom