Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We experimentally compare the performance of two multi-type environmental credit trading markets. The first trading market is called the multiple market (MM) institution, which allows the providers to sell jointly produced credits of all types. The second trading market is called the single market (SM) institution, where the providers of jointly produced credits can only choose one type of credit to sell. We investigate several key indicators, including the trading price, quantity, and net social benefit, to compare the performance of the SM and MM institutions. We find that the trading prices are significantly lower in MM compared to SM, indicating that MM potentially benefits the credit buyers. We also find that SM leads to more credit productions. Since not all credits can be traded in SM, the increase in the production cost outweighs the increase in the total social benefit. As a result, the net social benefit is lower in SM compared to MM. We expand the literature by firstly designing a market platform for multi-type credit trading and then assessing their performance with lab experiment evidence.