Townhomes under construction are seen in a new development in Brambleton, Virginia.ANDREW CABALLERO-REYNOLDS/Getty ImagesSome housing experts want Washington to take a bolder approach to policy reform.They want the federal government to target local and state land-use laws that stifle construction.They point to the national drinking age law as a model.There are two classic ways to encourage someone to change their behavior: a carrot or a stick.The federal government is much more likely to rely on incentives — or carrots — when it comes to housing policy.