In 1978, the Communist Party’s 11th Congress broke with its ideology-based approach to policy making, in favor of a more pragmatic approach, which Deng Xiaoping famously dubbed the process of “feeling our way across the river.” At its core was the idea that public action should be based on evaluations of experiences with different policies: this is essentially what was described at the time as “the intellectual approach of seeking truth from facts.” In looking for facts, a high weight was put on demonstrable success in actual policy experiments on the ground. The evidence from local experiments in alternatives to collectivized farming was eventually instrumental in persuading even the old guard of the Party’s leadership that rural reforms could deliver higher food output. But the evidence had to be credible. A newly created research group did field work studying local experiments on the de-collectivization of farming using contracts with individual farmers. This helped to convince skeptical policy makers (many still imbued in Maoist ideology) of the merits of scaling up the local initiatives. The rural reforms that were then implemented nationally helped achieve probably the most dramatic reduction in the extent of poverty the world has yet seen. (Ravallion 2008, 2; references not included)...
Some of the experiments that proved extremely successful were: the household responsibility system, dual-track pricing, township- and-village enterprises, and special economic zones... What is striking is that no fewer than half of all national regulations in China in the early to mid-1980s had explicitly experimental status.These are taken from Rodrik 2008, and the details are there. Note that this isn't necessarily about conducting rigorous randomized control trials, but simply adopting some form of experimental approach in policy making, seeing if some policy works perhaps at some localities first before implementing them nationally.
I am motivated to post this partially because I am somewhat concerned about the controversial Reproductive Health Act, which just passed with some controversy in the Philippines. It is a big win, in my opinion, given what I know about policies that affect women's health. But there does not seem to be any talk of evaluation. And it will be implemented in a large scale. Aren't we interested in whether it works not only in theory but also in practice?