价格测试中常犯的几个错误

报告出处:北京思捷讯管理咨询有限
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原作者:Albert Fitzgerald

翻译:黄艳霞

    传统的价格测试倾向于画出一条价格曲线以便我们可以在一定的价格范围内确定销量(也就是消费需求)。而传统的经济学教材往往把价格曲线要么描画成直线,要么就是平滑的曲线。我还记得我在大学里上的第一堂经济课,用的是被称为经济学圣经的 Samuelson 的教材,书中所有的价格曲线都异常地平滑。其中很多曲线甚至是直线,以此表明价格和销量间的简单关系:随着价格的升高,销量会随之减小。

    不过更典型的价格曲线是凹型的,表明当价格非常低时,销量不成比例地高。与之相似的是,即便价格很高时,仍有一些顾客(估计是那些对价格不敏感的人群)的购买量会保持不变。

不同价格点的需求弹性(价格敏感度)

    直线或平滑曲线型的价格曲线表明在所有测试的价格点上,价格敏感度是连续的。这意味着:当价格升高时,销量以确定的斜率下降。在经济学教材中,价格弹性也通常被称为需求弹性。凹型价格曲线显示:价格较高时,价格敏感度较低;而当价格较低时,价格敏感度较高。如图 2 所示:当价格从 100 元降到 70 元时,销量仅从 1 增加到了 2 ,说明尽管价格大幅下降,但选择购买的人并未显著增加;而当价格从 20 元下降到 10 元时,销量从 6 增加到了 10 ,有了显著提高,说明在这一价格范围内,市场需求的价格敏感度较高。支撑这一类型曲线的逻辑是:当价格较高时,多数对价格敏感的消费者已经不再购买,而剩下的少数则是那些对价格不太敏感的消费者,他们可以接受更高的价格。

图1

Z 型价格曲线

    在许多 B2B 或高科技产品的购买中,传统的平滑或凹型曲线显然与实际不符。很多定量研究结果表明:需求实际与价格的关系是呈现 Z 型曲线的。

    上图中我们假设了一个 Z 型价格曲线,它有明显的 3 段区域:当价格较低时(低于 30 元)价格敏感度较高,这与在平滑或凹型曲线中所表现的一致;在价格中等时(在 30-80 元之间),价格敏感度非常低,这与传统的价格曲线(平滑或凹型曲线)大相径庭,原本应该是价格敏感度居中的一段曲线;当价格较高时( 80 元以上),我们看到了与传统经济理论完全相反的事实,价格敏感度不但没有下降,反而代之以价格敏感度极高的曲线。

    这种现象我们不但能从大量的定量研究中发现,也会在定性研究中得意验证。这一结果表明在价格曲线上实际存在着 3 个区域:高价格敏感度同时存在于很低和很高的价格区间,而低价格敏感度则在一定价格范围 ( 即进行型价格 ) 内存在。

单一的采购程序能够解释 Z 型价格曲线

    要弄清为什么在不同的范围内价格敏感度有不同的变化,首先要弄清高科技产品和很多 B2B 产品的采购过程。我们可以采购笔记本电脑为例来做一个说明:商业采购尤其是高科技产品的采购,对于购买者来说存在较大的风险。一时的疏忽不仅会导致公司金钱的损失,也会影响到一个人的职业前途。而且,当一些隐性成本被包括进来的时候,如培训成本、 POTENTIAL DOWN TIME 、安装成本等,很多高科技产品的实际成本要比其报价高出很多。当这些成本都被考虑进去的时候,很多高科技产品以及商业产品的采购就会遵循一个相似的程序。在这个程序中,典型的购买者会经历 4 个阶段:

    第一阶段是认知阶段。在这一阶段,购买者通常会尽可能多地寻找资讯(比如查看一些电脑杂志),或询问经销商以及他们的同事,要求他们给出一些建议。这一阶段的主要任务就是对产品的相关特性以及可选范围有一个深入的了解。

    第二阶段是考虑阶段。这一阶段的主要任务是减少备选品牌。通常市场上会有上百种笔记本电脑可供选择,而购买者只选其中的很小一部分进行评估,这一筛选的过程往往是快速而未经深思熟虑的。到目前为止,购买者已经决定了一些他需要的关键性能,而且也对预算有了一个清晰的范围。我们把这一价格范围称为应付价格。在这一阶段,价格往往是决定品牌取舍的一个关键因素,同时应付价格的范围变得异常重要。那些超出应付价格上限的产品被自动排除在外;而一些在应付价格下限以下的产品通常会被评估,尽管按常理他们无需被评估。例如,当检视可选择的笔记本电脑时,购买者可能决定,在一些给定的特性下,他愿意支付的价格是 2000-3000 美元之间。那些超过 3000 元的产品就会被淘汰出去。然而,那些价格在 2000 元以下的产品却常常会继续进入下一阶段,尽管他们并不在预算范围之内(可能它并非身出名门)。换言之,这些产品之所以被评估盖因其数量众多。

    在第三阶段产品会被逐一评估。只有极少数的产品会被严格评估。然而一旦产品进入这一阶段,价格因素变得很不重要,而代之以对功能或性能的关注,这些因素往往在最终的购买决定中起着举足轻重的作用。这样的现象我不仅在定量的价格测试中看到过,也在小组座谈会和一对一的深访中看到过。最终的结果是在评估阶段价格变得不那么成比例地重要了,而是主要被用来去除那些不在考虑范围内的产品。由于只有那些或者在应付价格范围内或者价格超乎想象地低的产品会被严格评估,价格在这里只扮演一个很单纯的角色。每个产品的价格点都在应付价格范围内,这意味着,只要在这一范围内,就无所谓是选择价格最高的产品还是价格最低的产品,从而导致了较低的价格敏感度。

    在第四阶段,实际的购买行为发生了。

曲线重叠的原因

    人们可能认为在需求曲线图上不该有重合部分,因为每个人都有一个自己认为的合理的价格。然而,事实并非如此,对于很多高科技产品,我们发现不同的人愿意支付的合理的价格区间相差并不多。一个主要的原因应归功于高科技产品市场的原动力。高科技产品市场通常被一些所谓的大腕操纵着:这是少数一些在这个领域知识广博,深受尊敬,对整个市场具有极高影响力的人。

    对于大多数高科技产品来说,总有那么几位杂志的编辑堪称大腕。产品的价格区间常在这些发行量很大的杂志中被讨论,而那些价格不在这个范围内的产品就被排除在外了。尽管有时他们也会讨论一些价格高的产品,但这些产品几乎很难得到编辑们的青睐,他们同时会很清楚地告诉读者,他们对这个价格感觉太高了。相似的,价格的底线也是这样被划定的。任何熟悉计算机行业的人都会毫无例外地在无数杂志的封面看到类似这样的标题:奔腾机跌破 2000 美圆大关!

    这些大腕们之所以能够操纵市场,是因为要想对高速发展的高科技行业保持高度敏感简直不太可能。商业购买者只好依靠这些专家来指导他们的采购。这些专家为整个市场设置了价格区间,而这在消费品市场或工业品市场上是根本不可能的。如果一个产品有广泛的认知或与工业品相似的话,我们在价格需求曲线图上就不可能看到 Z 型曲线。例如,在台式机市场,由于很多消费者对它非常了解,少数大腕的预测就不足以左右市场价格,因而在这类产品中,价格曲线就会遵循传统的经济规律,被无形的市场之手所左右。

对 Z 型曲线的解释

    从 Z 型曲线我们可以得出一些隐藏的结论:

1.最大利润价格点当然会是在应付价格范围的最高点,但要注意:只要一过最高可接受价格点,销量会大幅下降。

2.低于应付范围下限的价格对获得显著的市场份额有较大帮助。个别商品低于成本价销售、降价、低价进入等都是很实际的例子 - 即便不是理论上的至少也是实践证明了的,许多公司已经意识到以较低的价格销售在获得较多关注、良好评价以及销量方面有非常显著的效果。

使曲线平滑的危险

    这些年来,我读过无数关于价格研究的文章,大多自觉不自觉地都假设得到的结果会符合一个曲线,而几乎没有哪篇文章会去探讨将曲线平滑化的危险。也许这是消除在曲线外的点的需要 - 客户要是看到原始数据的话会觉得很不舒服,或者更多地是因为目前在市场研究领域所应用的分析软件的缺陷造成的。很多软件都要求价格测试得到的数据应该是连续的百分比数值(而不是名义数据),以便推断在特定价格下的销量而不是那些实际测量的结果。例如: SPSS 联合分析的模拟模块要求程序价格分值是连续的数值(迫使所有的点都在一条直线上)而不是离散的数值(不在一条直线上),以便模拟那些在实际被测量数值之间的价格。 SPSS 为连续的价格点提供了两种基本的选择:要求所有点在一条直线上的线性模拟;或理想 / 非理想性模拟,一个二次方程模型,据此可以描绘出凹型曲线。

    下图描绘了如果一个研究人员试图将一条 Z 型价格曲线平滑化的后果。(图略)

    我们可以看到拐点消失了,从这个图上我们将无法选择最佳价格点。

以下是关于价格测试的几点注意事项

1.被测试的价格范围非常重要。我们建议在这个范围内应包含比最终实际应付价格略高及略低的一些价格点。当然这就引出了下面一个注意事项。

2.要充分了解购买决策的全过程以及最终实际应付的价格。我们的研究人员达成此目的的典型方法是通过一对一的访谈,小组座谈以及群体访问(主要是电话会议形式的小组座谈)

3.确定被测试的价格点的数量也非常重要。如果数量太少,则无法发现价格的拐点,从而无法预测最佳价格点。我们推荐最少测试 5 个价格点。同时这些价格点必须慎重选择。这样,尽可能多地选择与实际情况相接近的价格点来进行测试以便准确地预测拐点将在价格曲线的哪里出现。

4.在试图平滑化曲线的时候一定要小心。一条经过处理的价格曲线很有可能导致在计算利润最大化的价格点时产生巨大的误差。

5.这些价格点不一定是等距的,当然如果是,还是选择等距价格点进行测试为好。

 


Article QuickLink Number: 0110
Published: April, 1995

Does your pricing study make this common mistake?

Advanced technology products follow Z-shaped price curves

By: Albert Fitzgerald

Editor's note: Albert Fitzgerald is president of Answers Research, Inc., Solana Beach, Calif.

Traditional price studies attempt to create a price curve so that, within a range of prices, we can determine the quantity sold (i.e., relative demand). Traditional economics texts have typically drawn price curves as either straight lines or as smooth, concave curves. I remember my first college economics class using Samuelson's economics book (the "bible" of freshman economics). All of the price curves had a wonderfully smooth shape. Many were drawn as straight lines showing the simple rela-tionship that as price increases, the quan-tity that would be sold (i.e., demand) falls.

But more typically, the price curves were drawn with a concave shape (see next chart) demonstrating that as price gets very low, demand gets disproportionately greater. Likewise, even at very high prices, some people (presumably those who are not price sensitive) will continue to purchase in similar quantities.

Elasticity of demand (price sensitivity) at differing price points
A straight line or flat price curve indicates that for all prices tested, price sensitivity is constant. This means that as price increases, demand drops at a constant rate. In economics texts price sensitivity is generally referred to as the "demand elasticity." A concave price curve shows that price sensitivity is less at higher price points and greater at lower price points. This can be seen in chart 2. As price drops from $100 to $70, the quantity demanded increases from one to two units, showing that for a relatively large price drop, few additional people buy. However, when price drops from $20 to $10, the number of units sold increases dramatically from six to 10 units, demonstrating that, in this price range, the market is highly sensitive to price. The logic behind this type of price curve is that at high prices, most of the price sensitive people have already stopped buying and that the few people left are not very price sensitive and are willing to pay a high price.

Z-shaped price curves
For many business-to-business and advanced technology product purchases, the traditional flat or concave price curves do not seem to fit empirical evidence. We have found in many quantitative studies that demand actually follows a Z-shaped price curve.

In the above chart we show a hypothetical Z-shaped price curve. It shows three distinct sections. At lower prices (i.e., below $30) it shows a high sensitivity to price, similar to what we would expect to see in a flat or concave price curve. At middle price points (i.e., between $30 and $80) we see a very low sensitivity to price changes. This differs from traditional price curves (i.e., flat or concave price curves) which would indicate that price sensitivity should be medium. At higher price points (i.e., above $80) we see the exact opposite of what traditional economic theory would indicate. Instead of low price sensitivity, we see instead an area of very high price sensitivity.

We have both empirically derived this phenomenon in numerous quantitative studies as well as validated these results in qualitative studies. These findings indicate that there are, indeed, three distinct sections to the price curve -- high price sensitivity exists at both very low and very high prices while low price sensitivity exists over a range of prices we call "going prices."

Unique purchase process explains Z-shaped price curves
To understand why sensitivity to price varies over certain ranges of prices, it is first necessary to understand the purchase process for advanced technology and many business-to- business products. We can use as an example the purchase of a laptop computer. Business purchases, and especially advanced technology purchases, tend to be high risk purchases to buyers. Mistakes can have a high cost in terms of dollars and to one's career. In addition, the "true" cost of many high technology products can be much higher when intangibles such as training costs, potential down time, and installation costs are included. When all of these factors are taken into account, many advanced technology products and other business purchases follow a similar purchase process. In this purchase process, the typical buyer moves through four stages.

Stage 1 is the awareness stage. During this stage it is quite typical for a buyer to conduct a literature search (i.e., look at a review of notebook PCs in a computer magazine), or ask a reseller or colleague for recommendations. The main purpose of this stage is to become educated about the alternatives and features available.

Stage 2 is the consideration stage. The purpose of this stage is to reduce the number of products evaluated. There are literally hundreds of possible notebook PCs available on the market. During this stage the buyer selects a small subset for evaluation. This process of reducing the alternatives is often brutal and quick. By now the buyer has decided on the key features he requires and typically has a solid idea of what he should have to pay. We call this range of prices the "should-pay" prices. At this stage, price is often a key determinant in what products make the cut and the should-pay price range becomes extremely important. Products that exceed the should-pay ceiling often are automatically excluded. And several products which are below the should pay floor are often evaluated even though they would normally not be evaluated. For example, when reviewing available notebook PCs, the buyer may decide that for a given set of features he should pay between $2,000 and $3,000. Any product that exceeds the $3,000 ceiling never makes it to the next stage. However, products that are less than the $2,000 floor are quite often taken into the next stage even though they would not typically have been evaluated at expected prices (perhaps because they are from an unknown manufacturer). In other words, the product is evaluated because it is such a great deal.

In Stage 3 products are evaluated. Only the few products that made the short list are seriously evaluated. But once a product makes it to this stage, price becomes much less important and features/benefits are key in the final purchase decision. I have seen this validated not only empirically through pricing studies, but also through myriad focus groups and one- on-one interviews. The bottom line is that price becomes disproportionately important in the consideration stage and is used primarily to eliminate products from consideration. Since only those products that are either within the should-pay range or have an unexpectedly low price are seriously evaluated, price takes on a unique role. And individual price points are subordinate to the should-pay prices, meaning that as long as the price is within an appropriate range, it does not matter if it is on the high or low end--resulting in low price sensitivity.

In Stage 4 the actual purchase is made.

Reasons for the kink
One could argue that there really should not be kinks in the demand curve because each individual determines their own unique should-pay price range. However, in many advanced technology product categories, we have found that the should-pay price range varies little between individuals. One of the main reasons is due to the dynamics of advanced technology markets. Advanced technology markets are often highly influenced by gurus -- a few, highly knowledgeable, highly respected people who influence entire markets.

We find that for most advanced technology product categories, there are several magazine editors who fit this description of a guru. Price ceilings and floors are often talked about in magazine reviews with many publications excluding products that exceed ceiling prices. Even when they include higher priced products, these products rarely win Editor's Choice awards, and magazines are clear in saying if they feel the price is too high. Likewise, floor prices are defined. Anyone familiar with the computer industry will certain see plenty of magazine covers with headlines like "Pentium PCs break the $2,000 price barrier."

The reason gurus become very influential is because it is difficult to stay abreast of rapidly changing technology. Business buyers rely on experts to guide their purchases. These experts set price expectations for entire markets. This is rarely true for consumer or commodity products. We would rarely see a Z-shaped demand curve if the product has become well understood and commodity-like. For example, desktop PCs have become so well understood that gurus are much less influential in establishing should-pay prices. Therefore, price curves will often follow traditional economic theory, with the market's "invisible hand" creating more traditional price curves.

Interpreting Z-shaped price curves
Several important implications can be drawn from Z-shaped price curves.

1. The profit maximizing price point would typically be at the high end of the should-pay range. But caution must be exercised because pricing above the should-pay ceiling would result in a dramatic drop in sales.

2. Pricing below the "floor" has the effect of potentially gaining significant market share. Loss leaders, sales, and introductory prices are all pragmatic examples of how many companies have -- if not theoretically at least from experience -- recognized that going below the floor price has the effect of gaining significantly increased consideration, evaluation, and purchase.

Dangers of smoothing price curves
Over the years, I have read numerous articles on market research pricing studies which automatically assume that resulting data will be "fit to a curve." However, very few articles ever discuss the caveats and pitfalls of smoothing pricing data. Perhaps it is the desire to eliminate "outliers" -- data that would look weird if a client actually saw the raw data -- or more likely it is due to pragmatic considerations of current software packages commonly used in the research community. Many packages require that results from pricing research be treated as continuous ratio data (as opposed to nominal data) in order to extrapolate demand at prices other than those explicitly measured. For example, SPSS's conjoint simulation module requires that utility scores for price be treated as continuous data (i.e., forcing all points to sit on a line) rather than discrete (data which is not forced to fit a line) in order to simulate prices between those actually measured. SPSS gives basically two options for continuous pricing data: linear, which forces all points to fit a straight line; or ideal/anti-ideal, which are quadratic models which can be used to generate a concave price curve.

The chart below illustrates what might happen if a researcher were to smooth a Z- shaped price curve.

We can see that the inflection points would disappear. And it would be unlikely that an optimal price point would be chosen.

Here are some implications for pricing research:

1. The range of prices tested is very important. We recommend including prices which are higher and lower than the should-pay prices. Of course this leads to another important implication.

2. It is critical to understand both the purchase process for the product under study and the range of should-pay prices. Our staff typically accomplishes this using one-on-one interviews, focus groups or focused interviews (essentially telephone focus groups).

3. The number of price points tested is important. If too few price points are tested, it is unlikely that the inflection points (where the kinks appear) can be accurately predicted. We recommend testing a minimum of five price points. And those prices must also be carefully chosen. Therefore, test as many price points as is practical in order to accurately predict where the kinks are in the price curve.

4. Be cautious in smoothing price curves. A smoothed price curve could result in a serious miscalculation of the profit maximizing price point.

5. Price points do not have to be equidistant, as would likely be required if a smoothing algorithm were being used.

©1995  Quirk's Marketing Research Review (www.quirks.com). All rights reserved.

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