Living standards have soared during the twentieth century, and economists expect them to continue rising in the decades ahead. Does that mean that we humans can look forward to increasing happiness?

    Not necessarily, warns Richard A. Easterlin, an economist at the University of Southern California, in his new book, Growth Triumphant: The Twenty-first Century in Historical Perspective. Easterlin concedes that richer people are more likely to report themselves as being happy than poorer people are. But steady improvements in the American economy have not been accompanied by steady increases in people's self-assessments of their own happiness. "There has been not improvement in average happiness in the United States over almost a half century----a period in which real GDP per capita more than doubled," Easterlin reports.

    The explanation for this paradox may be that people become less satisfied over time with a given level of income. In Easterlin's word: "As incomes rise, the aspiration level does too, and the effect of this increase in aspirations is to vitiate the expected growth in happiness due to higher income."

    Money can buy happiness, Easterlin seems to be saying, but only if one's amounts get bigger and other people aren't getting more. His analysis helps to explain sociologist Lee Rainwater's finding that Americans' perception of the income "necessary to get along" rose between 1950 and 1986 in the same proportion as actual per capita income. We feel rich if we have more than our neighbors, poor if we have less, and feeling relatively well off is equated with being happy.

    Easterlin's findings, challenge psychologist Abraham Maslow's "hierarchy of wants" as a reliable guide to future human motivation.

    Maslow suggested that as people's basic material wants are satisfied they seek to achieve nonmaterial or spiritual goals. But Easterlin's evidence points to the persistence of materialism.

    "Despite a general level of affluence never before realized in the history of the world." Easterlin observes, "Material concerns in the wealthiest nations today are as pressing as ever and the pursuit of material need as intense." The evidence suggests there is no evolution toward higher order goals. Rather, each step upward on the ladder of economic development merely stimulates new economic desires that lead the chase ever onward. Economists are accustomed to deflating the money value of national income by the average level of prices to obtain "real" income. The process here is similar----real income is being deflated by rising material aspiration, in this case to yield essentially constant subjective economic well-being. While it would be pleasant to envisage a world free from the pressure of material want, a more realistic projection, based on the evidence, is of a world in which generation after generation thinks it needs only another 10% to 20% more income to be perfectly happy.

    Needs are limited, but not greeds. Science has developed no cure for envy, so our wealth boosts our happiness only briefly while shrinking that of our neighbors. Thus the outlook for the future is gloomy in Easterlin's view.

    "The future, then, to which the epoch of modern economic growth is leading is one of never ending economic growth, a world in which ever growing abundance is matched by ever rising aspirations, a world in which cultural difference is leveled in the constant race to achieve the goods life of material plenty, it is a world founded on belief in science and the power of rational inquiry and in the ultimate capacity of humanity to shape its own destiny. The irony is that in this last respect the lesson of history appears to be otherwise: that there is no choice. In the end, the triumph of economic growth is not a triumph of humanity over material wants; rather, it is the triumph of material wants over humanity."

    人們的生活水平在20世紀飛速提高，經濟學家預計在未來的幾十年里，人們的生活水平還會進一步提高。這是否意味著我們人類的日子有望越過越幸福呢？

    未必如此，南加州大學一位經濟學家理查德?A?伊斯特林在其新書《增長的勝利：從歷史的視角展望21世紀》中如是告誡世人。他承認，一般來說，富人比窮人更有可能稱自己是幸福的。然而，美國人對幸福感的自我評價并未伴隨著美國經濟穩步發展而有所提高。伊斯特林指出：“過去近半個世紀中，美國的實際人均國內生產總值增加了2倍多，而人們并未感到比以往更幸福。”

    對于這種自相矛盾的現象也許可作如下解釋，隨著時間的推移，人們對一定的收入會越來越不滿。用伊斯特林的話來說：“收入增加了，人們的期望值也相應提高了，期望值的提高會抵消收入提高所帶來的預期有所增加的幸福感。”

    伊斯特林似乎在說，金錢可以買來幸福，但這只有在自己金錢不斷增多，而別人收入不變的情況才會如此。他的分析有助于人們理解社會學家李?雷恩沃特的調查結果----從1950年到1986年，在美國持收入“必須維持基本生活”觀念的人隨著實際人均收入的增加而同比增長。如果收入比鄰居多，我們就會感到自己富有；反之，則覺得自己貧窮。由此可見，人們把幸福感與相對富裕程度等同起來。

    伊斯特林的調查結果向心理理學家亞伯拉罕?馬斯洛的“需要等級體系”理論提出了挑戰，該理論為人類未來的動機提供了可靠指南。馬斯洛認為：一旦人們的基本物質需求得到滿足后，就會轉而追求更高層次的精神需求。但伊斯特林的論證卻指出人類的物欲永無止境。

    伊斯特林還評述到：“盡管人類歷史上從未實現過普遍水平的富裕，但今日最富有的那些國家對物質的關注還是那么迫切，對物質需要的追求還是那樣的強烈。”這表明人類并未朝更高層次的精神目標進展。更確切地說，經濟發展每上一個臺階只會刺激新的經濟需求，進而促進經濟持續向前發展。經濟學家通常用國民收入的貨幣價值減去平均物價上漲額度來計算“實際”收入。同樣，人們日益增長的物質欲望，在此主要是持續不斷對經濟富裕的主觀要求，削減了實際收入。雖然設想一個沒有物欲壓力的世界是件愜意的事，但一個基于事實的更為現實的想法是設想在這樣一個世界里，世世代代的人們都認為只要將收入再提高10%--- -20%，就可達到無比幸福的境界。

    需求是有極限的，而貪欲卻無止境�？茖W再進步也尚未研制出治療嫉妒的良藥，因此只有當我們的財富讓鄰居相形見絀的時候，我們才會感到片刻的幸福。所以在伊斯特林看來，未來的前景不容樂觀：“當今經濟發展的趨勢告訴我們，未來經濟會不斷發展、永不停歇，未來世界會是一個財富不斷增長而欲望節節上升的世界；一個為達到富裕不斷角逐而導致文化差異盡失的世界；一個建立在信仰科學和智力并相信人類有最大的能力塑造自己命運的世界。具有諷刺意味的是，在最后一點上，歷史的經驗教訓似乎告訴我們事物的發展并非如此：人類別無選擇，并不能掌握自己的命運。最后，經濟發展的結果不是人性戰勝物欲，而是物欲戰勝人性。”