4 principles are key to constitutional design: degree of specificity, treatment of tradition, amendability, and incentive for compliance. Specificity is not necessarily an advantage. Napoléon once said that a constitution should be short and obscure.
Germany’s Basic Law may have averted another Hitler, but it has also provoked political paralysis. In 1972, the government of Willy Brandt had lost so much support in the parliament that it could not even get a budget passed. Brandt wanted to step down and call for a new election. For 6 months, no one could think how to accomplish this under the constitution’s complicated provisions, without Brandt’s party members voting themselves out of office, which they were unwilling to do.
In breaking with societal traditions, constitutions can lose their legitimacy. Outlawing alcohol consumption via constitutional amendment in the US backfired because it went against the long-standing American tradition of getting liquored up.
Sometimes tradition is exactly what constitution writers intend to break. Revolutionary states, such as China in 1949, have imposed new political systems that transformed societal expectations.
As constitutions are often imperfect documents in prognosticating a society’s future needs, there should be a way to sensibly amend them. Engineering such a mechanism has often proven problematic, especially when a constitution represents a struck bargain among conflicting interests.
Out of fear that a hard-fought compromise between states’ rights and federal power might be undone, the US constitution was designed to be difficult to change. As a result, aside a remiss citizen bill of rights, only 27 amendments have been made in over 2 centuries, and 2 of those amounted to nothing: the 18th Amendment prohibited booze, and the 21st rescinded it.
The lubricant for this inflexibility came from an unconstitutional power grab by the US supreme court to adaptively interpret the often-vague constitution. The result has been a history of caprice in constitutional law.
Denmark established its 1st modern constitution in 1849. Instead of amendment, the entire constitution has been replaced 4 times since (1866, 1915, 1920, 1953).
The 3rd principle is of incentive compatibility: a constitution should provide incentives for those in power to perform toward societal well-being.
In this, the US constitution fails miserably. Its lower legislative house is supposed to establish laws that benefit the country as a whole. Instead, the only incentive for house members is to serve the interests of those with power in their district. Exorbitant wasteful spending (called pork) is one result. Neglect of the powerless underclass is another.
If the US had stronger political parties, which could punish errant members, the personal incentives would be different. Instead, weak parties leave a severe incentive problem.