历史数据 tells you the Taiwanese economic growth is slower since the 90s, but it does not tell you why it slows. Linking it to democracy is just one of your 假设的推断。In my opinion, Taiwan's economy slows since 90s mainly due to competition from the mainland. Production and jobs have been relocated to mainland to take advantage of cheap labor cost which cause the island's economy to slow. This is not going to change whether Taiwan is a democracy or not.