"There's a general realisation now that, if we're going to keep test cricket going well into the future, we can't just say it's going to survive on its own," Richardson said.
"Unless we can give some meaning to these series beyond the rankings and a trophy, then interest in test cricket will continue to waiver. The same applies if we allow uncompetitive test cricket to take place too often."
Richardson said the number of test countries cannot drop but "we have to create a proper competition structure which provides promotion and relegation and opportunities to get to the top.
"The beauty of leagues is that, in theory, you will have a more competitive competition and teams playing each other that are of a more equal standard.
"They will all be striving for something. There's something at stake. Hopefully that will inspire performance and make the matches more competitive."
New Zealand are currently ranked fifth in test cricket, behind Australia, India, Pakistan and England.
Richardson also confirmed plans to stage an extra world T20 tournament in 2018, likely to involve "a minimum" of 16 teams and to be staged in either South Africa, Sri Lanka or the United Arab Emirates. The final decision will be made by the ICC's broadcasting partner Star.