【正文】 A manager acting in an economically rational manner should, at any given point in time, evaluate the net present value of future decisions and not be affected by past decision. Simply put, is it better to divest or to continue ownership?A substantial amount of evidence has shown that the assumption of economic rationality is routinely violated by managers. It is well documented managers may exhibit an escalation of mitment to a failing course of action. There are at least two approaches to risk taking that would motivate predications within this context.One approach to the escalation of mitment phenomenon has been the selfjustification hypothesis. Brockner, (1986) has written escalation is determined, at least in part, “by decision makers’ unwillingness to admit that their prior allocation of resources to the chosen course of action was in vain (the selfjustification hypothesis).”O(jiān)ften managers do not want to admit defeat and will go to great lengths to show their decisions were ultimately justified. This explanation is parable to the finance literature/s managerial hubris concept, which says managers really believe they can achieve the required gains from the acquisition. Some research has even suggested managers may escalate their mitment to a failing acquisition such that the divestment decision is severely delayed.The concept of escalating mitment has also been approached from the prospect theory perspective. Prospect theory predicts that individuals will generally be risk seeking when they are losing but risk averse when they are winningclassic gambling behavior. Winning or losing is in relation to an arbitrary reference point. The acquisition premium provides a clear target reference point for managers to use.Then, as managers miss what may actually be unachievable performance targets and fall below their target reference point into the domain of losses, they may increase their level of risk taking to attempt to upset these targets in the future. The analogy to this is a gambler sitting at a blackjack table who increases his bets as he loses. These higherrisk strategies may simply be perceived as necessary by managers given the distance they must cover to preserve value. For example, recall when synergies failed to materialize in ATamp。T spent millions on new sales teams in new markets and industries where it had little experience.Since higher levels of the acquisition systematic risk will be associated with a greater likelihood of not achieving performance targets, it follows high levels of the premium will also be associated with increases in risk taking.Very little research has been done in the area of the effect of acquisitions on risk taking. Lubatkin and O’Nelii (1987) and Chatterjee and Lubatkin (1990) find larger decreases in systematic risk “than an investor can do his own” for relate mergers than unrelated merges. Unrelated mergers, however, are found to have larger absolute levels of systematic risk according to Chatterjee and Lubatkin (1990).As with the majority of the management literature on acquisitions。模型清楚地說(shuō)明，當(dāng)溢價(jià)超過(guò)某種程度時(shí)，意識(shí)到采取有效防范措施的可能性也就越小。本次討論主要關(guān)注對(duì)收購(gòu)產(chǎn)生的系統(tǒng)性風(fēng)險(xiǎn)的預(yù)測(cè)，以及溢價(jià)收購(gòu)所產(chǎn)生的后果。從并購(gòu)之后的角度來(lái)看，管理風(fēng)險(xiǎn)的變化來(lái)自于兩個(gè)方面：(1) 在當(dāng)前激烈的競(jìng)爭(zhēng)游戲中，所下的賭注的范圍越來(lái)越大(如一個(gè)重大的廣告活動(dòng))；(2)資源投入到風(fēng)險(xiǎn)更高新的競(jìng)技游戲或兩者兼而有之。但是要考慮到隨著收購(gòu)溢價(jià)的增加，管理者很可能會(huì)忽視他們的業(yè)績(jī)，風(fēng)險(xiǎn)承擔(dān)水平是否隨時(shí)間而改變。僅僅需要考慮是需要?jiǎng)冸x資產(chǎn)呢還是繼續(xù)持有。這是有據(jù)可查的，在失敗的行動(dòng)中，管理者可能會(huì)給出一個(gè)升級(jí)的承諾。自我辯解假說(shuō)是實(shí)現(xiàn)承諾升級(jí)現(xiàn)象的途徑之一。這個(gè)解釋與金融界上的管理傲慢理論很相似。還有一些研究認(rèn)為管理者在失敗的收購(gòu)中提升承諾會(huì)使得撤資的決定被嚴(yán)重推遲。收購(gòu)溢價(jià)為管理者提供了一個(gè)明確的目標(biāo)參考點(diǎn)。就好像一個(gè)在賭場(chǎng)上賭輸?shù)馁€徒坐在酒桌旁，這無(wú)疑是會(huì)增加他的堵住的。例如，在ATamp。由于收購(gòu)的系統(tǒng)性風(fēng)險(xiǎn)越高，無(wú)法事項(xiàng)戰(zhàn)略目標(biāo)的可能性也就越大，同時(shí)，高溢價(jià)也會(huì)使承擔(dān)的風(fēng)險(xiǎn)增加。Lubatkin、O’Nelii (1987)，Chatterjee、Lubatkin (1990)發(fā)現(xiàn)，亦非相關(guān)合并相比，相關(guān)合并在降低單個(gè)投資者無(wú)法通過(guò)投資組合降低的系統(tǒng)風(fēng)險(xiǎn)上更有用。和大多數(shù)有關(guān)并購(gòu)管理的文獻(xiàn)的觀點(diǎn)一樣，這一結(jié)果是不容置疑的。但是在收購(gòu)以后風(fēng)險(xiǎn)承受程度已產(chǎn)生變化的這一理念還未廣泛接納。管理措施并不是在封閉的環(huán)境中執(zhí)行的，所以考慮管理團(tuán)隊(duì)在采購(gòu)后采取何種管理手段是很重要