任何一个政权，如果想长久维持，都知道必须防止那些握有权利的人利用权利谋取私利而损害该政权的利益，损害该政权持续存在的经济与政治基础。

罗马帝国也不例外。

罗马帝国是如何在制度上推行廉政呢？《罗马帝国消亡史》（THE DECLINE AND FALL OF THE ROMAN EMPIRE )第十七章是这样记载的（注意：这部历史巨著写于1782年左右，相当于清乾隆47年）：

“the strictest regulations were established, to exclude any person, without the special dispensation of the emperor, from the government of the province where he was born; and to prohibit the governor or his son from contracting marriage with a native, or an inhabitant; or from purchasing slaves, lands, or houses, within the extent of his jurisdiction.”

简单地说，罗马帝国有两条规定：（1）严格禁止任何人在其出生地省份的政府当官；（2）政府的官员及其儿子不得与其管辖范围内的人结婚，也不得在其管辖范围内购置奴隶、土地以及住房。《罗马帝国消亡史》的作者Edward Gibbon特别批注到：“ The same regulation is observed in China, with equal strictness, and with equal effect.”  就是说，同样的规则在中华帝国同样被严格执行，而且效果也相同。

什么效果呢？腐败现象仍然普遍存在。“the emperor Constantine, after a reign of twenty-five years, still deplores the venal and oppressive administration of justice, and expresses the warmest indignation that the audience of the judge, his despatch of business, his seasonable delays, and his final sentence, were publicly sold, either by himself or by the officers of his court. The continuance, and perhaps the impunity, of these crimes, is attested by the repetition of impotent laws and ineffectual menaces.” 康士坦丁皇帝在统治了25年之后，依然在哀叹贪赃枉法行为屡禁不止。类似的，如果看中国古代的朝代，即使有最严苛的法律，也还是有不怕死的贪官。

根据《中国共产党党员领导干部廉洁从政若干准则》，当前中国的制度似乎更为完善，该准则不准党员干部本热及其【配偶、子女及其配偶】在其所辖地从事商业活动之外，还有几十条规定，在监督方面，提出【发挥民主党派、人民团体、人民群众和新闻舆论的监督作用。】但从那些被抓的贪官的案例来看，效果明显欠佳。

美国的廉政相对可能还是做得比较好的。差别可能在于美国有强制性的财产申报制度。官员每年必须把所有财产准确地申报。如果发生错漏，可能会被立刻刑事起诉。近年有一名阿拉斯加的参议员就因为没有申报一笔十几万的隐性获利而被刑事起诉，在联邦法院被折腾得脱了好几层皮。

财产申报制度不能杜绝贪官，却能帮助更早地发现贪官。