Happiness is a standard by which Governments should measure their effectiveness. This is because a joyful populace is more productive and commits much less crime than an unhappy population. More good things happen in a country when people are happy: we treat each other well and are able to take care of ourselves and our families successfully too.
While happiness is a very broad term, for Governments to measure their effectiveness by, it is obvious, that if the policies, introduced and enacted, are appealing to the people, as well as effective, these happy people are likely to be proud of their country and its Government. The opposite of this scenario, results in unhappy people and unhappy people are more likely to conspire amongst themselves, to figure out a means of solving the problem, even if solving the problem includes rebelling and abolishing the current system of Government, or its leaders.
For example, if a government makes laws that an overwhelming amount of a country's people are against, people will be more likely to break them and, in turn, be punished for doing so. Imagine how all the people in Socialist countries feel being dictated what they can and can't do and getting in trouble for doing things that they should have every right to do. A country's people aren't unhappy unless the government is one that doesn't allow freedom to do as you please (aside from whats prohibited by basic necessary laws) and basic human rights. (exp. China)
When a government is effective, people follow the rules and laws. People follow the rules and laws when they feel their existence makes sense and is reasonable. When laws are reasonable, people are happy.
Because first of all, happiness is a person's opinion, therefore different for everyone and we would first need a way to measure happiness. Secondly, the government's job is not to make the people happy, their job is to make sure the country, province, or state is working properly, meaning that they aren't in debt, their imports and exports are good, the law is being uphelp or changed, etc..
And lastly, who's happiness would they measure? The entire populations, or just a majority of it?
A successfully run government should have a population of people who are very happy. Our constitution indicates that everyone should be able to have the pursuit of happiness. This means that everyone should have a chance to achieve happiness. Our government should consider their results based on happy people because it is what our country was founded on.
Its just an impossible thing to really measure, even on a small scale, let alone on a large one that people would try to influence. There would inevitably be people who would try to influence things for some reason, and it would not really serve any useful purpose in real terms.
No, happiness is not the way that governments should monitor their effectiveness, because all of the people in North Korea are happy all the time. Happiness is a subjective thing. It is very hard to measure effectively, and there is no reason to believe that countries like North Korea would tell the truth about their people's happiness.