At least that's the theory. But when Gavin Cassar, a Wharton accounting professor, checked this concept, he discovered something worrying: Some accounting devices not only fail to help businesspeople, but may really lead them astray. In one of his latest studies, forthcoming in up to date Accounting Research, Cassar displayed that making allowance for didn't help a assembly of Australian firms accurately outlook their revenues. In a second paper,he discovered that the groundwork of financial projections supplemented to aspiring entrepreneurs' optimism, premier them to overestimate their subsequent levels of sales and employment.