1/2 We do not have here haphazard data but a first and basic feature of technical progress. According to a formula that A. Merlin used about the crisis in America, especially in the computer market (1985-86), we try to analyze but we do not understand. As he also stated, the most convinced optimists need time to find encouraging signs. No path is without its stars. But the feature of technical progress is precisely that it is without stars. Its growth is causal, not final.