DUBLIN, Ireland —The housing affordability crisis that has frustrated young Americans for a decade has now taken hold in many big cities in Europe and beyond. The common threads: robust job growth, rising demand and not enough new development, causing rents and sales prices to rise faster than wages. Globally, homes are now less affordable than they were in the run-up to the 2008 housing crisis. …The resulting housing crunches are eroding living standards for poor and middle-class workers, intensifying wealth inequality and stoking political tensions. …In the 50 years through 2021, the countries with the sharpest rise in home prices around the world have been New Zealand, the U.K., Canada, Australia and Ireland. …Politicians in Canada, the U.K., Australia, Germany and South Korea are trying to boost construction by easing rules, including opening up undeveloped land for construction. National governments, though, are hamstrung by state and local rules that favor existing homeowners over renters, Hughes and Hilber said.