More free votes and performance-based government: you actually measure outcomes. Rather than just guessing, ideologically, “I think this is good”, well, count: “This is actually reducing crime” or “This is actually increasing crime.”
I always give the example of the Republican right in the United States, which has become soft on crime again. It wasn't because they changed ideologically; they figured out that if you put people in jail for 10 years rather than giving them a chance to rehabilitate, you have destroyed them as potential contributors to the economy, you have made a mess of their family, and this is hurting everybody. It wasn't because people woke up and had an ideological epiphany.
On a great many issues, I think there is a lot more room for consensus than we have. If we would actually be willing to reason together and look at statistics, facts, and the lessons of experience, we could achieve a lot more consensus, but you have to be prepared to measure stuff and measure it dispassionately: independent budget office at Parliament and credible independent metrics, metrics that don't change.
One of the books I am working on right now is studying the international experience with happiness metrics. The United Kingdom is innovative in terms of measuring well-being.
I have about 30, but if you ask me to list the top two, I would say more metrics and more free votes in Parliament. The one that is less talked about is the metrics stuff: actually measuring outcomes rather than thinking that because we have an ideology, it corresponds to reality. To get to a more consensus-based, more pluralism-based, and better government, being more open to empirical evidence and letting reality tell us what's happening rather than ideologically dictating reality, I think that would be a reform that all governments would benefit from.