It's very hard to say. The economy would depend greatly on Japan's ties with other countries, both in East Asia and in the West. By "keeping up the Taisho era", I assume you mean that Japan avoids its gradual entanglements in Manchuria, and certainly its full-scale war in China. This would require scaling down the power of the military, which was happening in the 1920s, and public opinion turning against war, which was also happening to some extent. The challenge is maintaining this after the Great Depression, which is the point at which militarism resurges. Japan's campaigns in Manchuria were motivated by an odd mix of prestige and resource-hungriness. It's quite a challenge to have people convinced that modernisation can be achieved by trade, especially when relations with the United States in particular and the West in general were quite fraught.
If this does succeed though, I'd expect relations to eventually thaw with the Western powers, and for there to be an uneasy truce with Nationalist China. Japan's economic rise would be less meteoric than it was IOTL post-war, I think. There would certainly not be the economic aid from the United States, and trade would continue to be focused on China. Moreover, a great part of Japan's post-war miracle IOTL can be ascribed to Yoshida Shigeru's decision to consciously avoid rearmament, which would drain the country of resources. It's heads up whether Japan ITTL devotes a too large proportion of its economy to the military. My guess as regards Japan's economic status in the present day ITTL is that it will still be less powerful than that of most of the West, but will be stable and functional. Hard to say; too many butterflies.
Culturally, it would probably still be quite socially conservative. The main difference would be the lack of Westernisation, which would be most striking in the cityscapes, tastes in decoration, clothing, etc.
Politically, I imagine that it'd shift more and more towards the British model. There would probably be an unspoken agreement that the Emperor doesn't interfere in politics, and the appointed Prime Minister would be leader of the party with the greatest number of seats. Similar to OTL, but less explicitly defined. You could expect to still have the aristocracy in place. The elephant in the room is the status of the military.
As a student of the Japanese language, I find it fascinating how different Japanese would be in this timeline. Hiragana and katakana would both be used interchangeably, for example. Formal documents would retain their classical language. For that matter, would shintaiji (character simplification) be introduced, or would Japan continue to use traditional Chinese characters? Depending on the state of nationalism, loan words may be avoided, and Japanese may have more words for pieces of technology, like Chinese does. If Korea and Taiwan become bilingual, they would probably have distinctive accents and dialects, and almost certainly a lot of Korean words would become commonplace in Chosen-Japanese.
At least, that's my speculation. It's my first post, so I may need to acclimatise.