<prompt> Translate the following text to EnglishKwa mujibu wa watafiti, kwa mfano, makadirio ya muda mrefu yanaweza kuwa na upendeleo wa juu na kwa muda mfupi inaweza kuwa na upendeleo wa chini.  <response>: Various reviewers have argued that 1 the long-term estimates may be biased high andor 2 the short-term estimates may be biased low. 