It was enjoyable to read all these informative comments above. :-)
Much of the real-world market design research focuses on fixing or replacing the existing markets when there is a problem or at the request of policymakers or institutes. Perhaps one empirical research trend is to move from reactive approaches to more proactive ones. (I am not trying to change market design's normative approach, although our approach is not yet perfect; e.g., Hitzig (2018) points out the Boston school choice's normative gap from social justice, https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3242882
). I think practical market designers (not pure theorists) can make greater contributions by rebalancing the focus from reaction to prevention/invention, and from the inward critical thinking to the outward entrepreneur thinking (e.g., https://people.stanford.edu/athey/sites/default/files/economists_in_tech.pdf
The new paper released two days ago by Alex, Tommy, and their team on Annie MOORE is an excellent example of the proactive way of research (https://project.nek.lu.se/publications/workpap/papers/wp16_11.pdf
). We can expect that the software's long-term significant impact will improve the living conditions for refugees. And Tommy has suggested dissertation-worthy topics in his comments above.
Al has pointed us in promising new directions in his comments above. His views are long reaching into the coming century, :-D, but he has not mentioned his own exciting work on the Global Kidney Exchange Program (https://paireddonation.org/
). This program also exemplifies the proactive approach. We can expect this program to involve more countries over the coming decades, but how we can achieve an optimal outcome from the long-run global perspective is still under-explored. In practice, like Annie, this is a complex system that we need to solve. How do we price surgery for a particular patient, given her demographic, health, and economic conditions? How do we design the insurance scheme? Which hospital should she go to for the operation? If she has to be transferred to a hospital abroad, and if it is urgent, shall there be passport-free travel? How long should she wait? Which country and from whom should she receive the kidney? How should we compensate the donor? What is the trade-off between life-expectancy and life-quality (or compatibility of the kidney)? Etc. In such a high-dimensional design space, perhaps the block-chain based data equipped with artificial intelligence could powerfully help us.
Eric Posner and Glen Weyl's book Radical Markets (http://radicalmarkets.com/
) gives another nice example for the proactive approach. For instance, it dedicates the whole of chapter 5 to the idea of "data as labor," redefining the economic relationship between ourselves and services like Facebook. (The other chapters are also eye-opening, offering innovative reform proposals on properties, voting, immigration, and corporate governance. The authors envision a future that is far better than what we have today. They also developed an APP called "weDesign" for quadratic voting.) How we design such a data labor market in the real world is worth exploring. How do we motivate data workers to provide quality data, and help them navigate the complexities of digital systems without overburdening their time? (this might also relate to the trichotomous preference mentioned by Tommy above?). It involves designing contracts as well as digital platforms, providing quality certification (probably using AI/ML methods), offering career development advice, balancing the bargaining power between monopsony data giants and data workers, and so forth.
Admittedly, there is always a gap between theory and practice, as so many politicians and policymakers are trapped by a small-bore mentality, and many designs face challenges from social norms and social justice. However, for the open, free, and market-friendly internalism to prosper, small fixes will not do. It is time for visionary radicalism at the center.
To conclude, the main messages I want to convey are: Practical market design can be taken place at the local, national and global level, but it would be beneficial if we always have a global mindset. The world needs more entrepreneur-minded market designers, as well as more market-design-minded entrepreneurs.
p.s. I will start to work as a researcher in a job-matching tech company next week, so it is really nice to see Bobby, John, Susan, and Mike's advice on online markets in this thread. They are very helpful to me :)