Emily Oster: What do we really know about the spread of AIDS?

翻译人员: Jie Zhao 校对人员: Zheng Li

So I want to talk to you today about AIDS in sub-Saharan Africa.

我今天要谈论的是在撒哈拉沙漠以南的非洲那里艾滋病的情况

And this is a pretty well-educated audience,

我知道在场的观众都受过很良好的教育

so I imagine you all know something about AIDS.

所以我可以猜想到你们都了解一些关于艾滋病的事情

You probably know that roughly 25 million people in Africa

你可能知道在非洲大约有两千五百万人

are infected with the virus, that AIDS is a disease of poverty,

感染了这种病毒，艾滋病是一种因贫穷而带来的疾病

and that if we can bring Africa out of poverty, we would decrease AIDS as well.

如果我们能让非洲摆脱贫困，我们就能同样减轻艾滋病疫情

If you know something more, you probably know that Uganda, to date,

如果你了解足够多的话，你可能知道迄今为止乌干达

is the only country in sub-Saharan Africa

是唯一一个在撒哈拉以南非洲的国家中

that has had success in combating the epidemic.

成功防治艾滋病

Using a campaign that encouraged people to abstain, be faithful, and use condoms --

启用了鼓励人们禁欲，忠贞，并使用安全套的运动

the ABC campaign -- they decreased their prevalence in the 1990s

被称为ABC准则。在九十年代它们大大减少了艾滋病的传播

from about 15 percent to 6 percent over just a few years.

仅仅几年内就从百分之15减到了百分之6

If you follow policy, you probably know that a few years ago

如果你关心时政，你可能知道几年前

the president pledged 15 billion dollars to fight the epidemic over five years,

总统承诺动用150亿美元在五年间抗击疫情

and a lot of that money is going to go to programs that try to replicate Uganda

一大部分钱都会被用来启动一些项目试图仿造乌干达

and use behavior change to encourage people and decrease the epidemic.

用行为变革来引导人们并减少疫情。

So today I'm going to talk about some things

然而今天我想讲一些

that you might not know about the epidemic,

你们可能不知道的事情

and I'm actually also going to challenge

事实上，我同时会颠覆

some of these things that you think that you do know.

一些你们自以为知道的事情

To do that I'm going to talk about my research

要做到这些我就要讲一下

as an economist on the epidemic.

我作为一个经济学家所做的研究。

And I'm not really going to talk much about the economy.

我不是真的要谈经济

I'm not going to tell you about exports and prices.

我不会谈论什么出口和价格。

But I'm going to use tools and ideas that are familiar to economists

但我会用一些经济学家们熟悉的工具和思想

to think about a problem that's more traditionally

去思考一个习惯上被认为是

part of public health and epidemiology.

在公共卫生和流行病学领域的问题

And I think in that sense, this fits really nicely with this lateral thinking idea.

在这个意义上，这真的很符合横向思维的方式

Here I'm really using the tools of one academic discipline

我会用某个学科的一些工具

to think about problems of another.

来思考另一个学科一些问题

So we think, first and foremost, AIDS is a policy issue.

我想首先来说，艾滋病是一个政策的问题

And probably for most people in this room, that's how you think about it.

可能对于在这个房里的大多人来说，你们就是这么想的。

But this talk is going to be about understanding facts about the epidemic.

但这次的演讲是有关于理解疫情传播的实事

It's going to be about thinking about how it evolves, and how people respond to it.

有关于思考它如何逐渐形成，人们又是如何应对的

I think it may seem like I'm ignoring the policy stuff,

我可能会忽略政策一类的东西

which is really the most important,

实事它们是最重要的

but I'm hoping that at the end of this talk you will conclude

我希望在演讲完毕你们能知道

that we actually cannot develop effective policy

我们无法实施有效的政策

unless we really understand how the epidemic works.

除非我们明白的疫情是如何发生的

And the first thing that I want to talk about,

我想讲的第一点

the first thing I think we need to understand is:

我认为我们必须理解的第一点是

how do people respond to the epidemic?

人们如何应对这种流行病的

So AIDS is a sexually transmitted infection, and it kills you.

艾滋病是经由性传播感染的，它足以致命。

So this means that in a place with a lot of AIDS,

也就是说在一个艾滋病泛滥的地方

there's a really significant cost of sex.

性交带来的代价也十分大

If you're an uninfected man living in Botswana, where the HIV rate is 30 percent,

在博茨瓦那艾滋病感病率是百分之30，如果你是此处的未感染者

if you have one more partner this year -- a long-term partner, girlfriend, mistress --

如果你今年将多一个长期的伴侣，或许是女友，或许是情妇

your chance of dying in 10 years increases by three percentage points.

在十年内可能死去的概率会提高三个百分点

That is a huge effect.

这种影响是巨大的

And so I think that we really feel like then people should have less sex.

所以我们会意识到，人们真的需要减少性行为。

And in fact among gay men in the US

事实上在美国的男同性恋中

we did see that kind of change in the 1980s.

在八十年代我们确实看到了这种改变

So if we look in this particularly high-risk sample, they're being asked,

如果我们调查这个独特的高危人群，当他们被问到

"Did you have more than one unprotected sexual partner in the last two months?"

在过去的两个月里你是否有多于一个未采取保护措施的性伴侣时

Over a period from '84 to '88, that share drops from about 85 percent to 55 percent.

数据表明从84到88年，比例从百分之85下降到百分之55

It's a huge change in a very short period of time.

在如此短的时间里，这是一个巨大的变化。

We didn't see anything like that in Africa.

在非洲我们从未看到这样的改变。

So we don't have quite as good data, but you can see here

我们没有这么好的数据，但你会发现

the share of single men having pre-marital sex,

单身男人婚前性行为

or married men having extra-marital sex,

或者已婚男人的婚外性行为的数据比例

and how that changes from the early '90s to late '90s,

如何从九十年代初到九十年代末，

and late '90s to early 2000s. The epidemic is getting worse.

从九十年代末到二十世纪初是如何变化的。疫情的传播变得更加严重。

People are learning more things about it.

人们对疾病的了解更多了

We see almost no change in sexual behavior.

但在性行为上却几乎没发生变化。

These are just tiny decreases -- two percentage points -- not significant.

仅仅有两个百分点的微小减弱

This seems puzzling. But I'm going to argue that you shouldn't be surprised by this,

这似乎很令人困惑，但我要说你不应该对此感到吃惊。

and that to understand this you need to think about health

想要理解这个，你需要用经济学家的思维

the way than an economist does -- as an investment.

来考虑有关健康的事 用一种投资的思想

So if you're a software engineer and you're trying to think about

如果你是一个软件工程师 当你在思考

whether to add some new functionality to your program,

在你的设计里是否要加一些新的功能时

it's important to think about how much it costs.

要花费多少成本是必须要考虑的。

It's also important to think about what the benefit is.

能带来多少利益也是必须要考虑的。

And one part of that benefit is how much longer

其中有一点就是你认为

you think this program is going to be active.

这个设计会在多长时间内有效。

If version 10 is coming out next week,

如果第十版会在下周发行，

there's no point in adding more functionality into version nine.

就没有必要在第九版中再加功能了。

But your health decisions are the same.

而你的健康选择也是如此。

Every time you have a carrot instead of a cookie,

每一次你放弃饼干而去吃胡萝卜时

every time you go to the gym instead of going to the movies,

每一次你去健身中心而不是去电影院时

that's a costly investment in your health.

这就是对你健康的极大投资。

But how much you want to invest is going to depend

但你要投资多少就取决于

on how much longer you expect to live in the future,

你预期能活多久

even if you don't make those investments.

就算你不做这些投资

AIDS is the same kind of thing. It's costly to avoid AIDS.

艾滋病也依旧存在 避免艾滋是花费巨大的

People really like to have sex.

人们真的很喜欢做爱。

But, you know, it has a benefit in terms of future longevity.

就未来长寿而言，它确实有好处。

But life expectancy in Africa, even without AIDS, is really, really low:

但在非洲的平均寿命，即使没有艾滋病，依旧非常非常低：

40 or 50 years in a lot of places.

在大部分地方是40到50岁。

I think it's possible, if we think about that intuition, and think about that fact,

可能的话，我们用直觉想想，结合实事想想，

that maybe that explains some of this low behavior change.

这或许能解释一部分这种低行为变革的原因。

But we really need to test that.

但我们急需检测一下。

And a great way to test that is to look across areas in Africa and see:

一种很好的检测方法就是调查非洲的各个地区：

do people with more life expectancy change their sexual behavior more?

在平均寿命高的地方人们改变性行为的习惯是不是多一些？

And the way that I'm going to do that is,

我想做的就是

I'm going to look across areas with different levels of malaria.

去调查有着不同疟疾疫情的地区。

So malaria is a disease that kills you.

疟疾是一种致命的疾病。

It's a disease that kills a lot of adults in Africa, in addition to a lot of children.

在非洲它使无数的成人和儿童失去生命。

And so people who live in areas with a lot of malaria

那住在疟疾病率高的地方的人们

are going to have lower life expectancy than people who live in areas with limited malaria.

将比疟疾爆发不严重地方的平均寿命要低一些

So one way to test to see whether we can explain

所以检验的一种方法就是我们是否

some of this behavior change by differences in life expectancy

能将平均寿命的差异与行为变革相联系

is to look and see is there more behavior change

并看看在疟疾疫情较轻的的地区

in areas where there's less malaria.

是不是行为变革就越多。

So that's what this figure shows you.

大家看看这些数据

This shows you -- in areas with low malaria, medium malaria, high malaria --

你会发现在疟疾疫情不同的地区

what happens to the number of sexual partners as you increase HIV prevalence.

当艾滋病感染率变高时性伴侣的数量如何变化

If you look at the blue line,

看这条蓝线

the areas with low levels of malaria, you can see in those areas,

在这些疟疾疫情较轻的地区

actually, the number of sexual partners is decreasing a lot

性伴侣的数量在巨减

as HIV prevalence goes up.

当艾滋病感染率变高的时候

Areas with medium levels of malaria it decreases some --

在中度疫情的地方也减少了一些

it doesn't decrease as much. And areas with high levels of malaria --

但没那么多。在重度疫情的地区

actually, it's increasing a little bit, although that's not significant.

也减少了一点点，但非常不显著

This is not just through malaria.

不仅仅是通过疟疾。

Young women who live in areas with high maternal mortality

在这片地区年轻妇女有着高孕产妇死亡率

change their behavior less in response to HIV

为应对艾滋病而改变的行为也比

than young women who live in areas with low maternal mortality.

那些同地区低孕产妇死亡率的女性少些。

There's another risk, and they respond less to this existing risk.

当有另一个威胁时，他们这种威胁的顾虑少些。

So by itself, I think this tells a lot about how people behave.

就此而言，它告诉我们许多人们如何行为的事实。

It tells us something about why we see limited behavior change in Africa.

它说明了在非洲行为变革十分有限的原因

But it also tells us something about policy.

同时也说明了一些关于政策的事情

Even if you only cared about AIDS in Africa,

就算你只关心在非洲的艾滋病情况

it might still be a good idea to invest in malaria,

投资治理疟疾也是一种不错的想法

in combating poor indoor air quality,

可以改进室内欠佳的空气质量

in improving maternal mortality rates.

降低孕产妇死亡率

Because if you improve those things,

因为你一旦改进这些

then people are going to have an incentive to avoid AIDS on their own.

人们就会自觉地防治艾滋病

But it also tells us something about one of these facts that we talked about before.

但它同样也说明了一个我们之前讨论过的事实

Education campaigns, like the one that the president is focusing on in his funding,

教育运动 就如同总统用他的资金所致力的那样

may not be enough, at least not alone.

是不够的 至少单独是不行的

If people have no incentive to avoid AIDS on their own,

如果人们没有防治艾滋病的自觉

even if they know everything about the disease,

就算人们知道了疾病的知识

they still may not change their behavior.

他们也不会改变自己的行为

So the other thing that I think we learn here is that AIDS is not going to fix itself.

我们必须了解的另一点是艾滋病不会自我修正

People aren't changing their behavior enough

人们的行为改变不足以

to decrease the growth in the epidemic.

减弱传播的增长

So we're going to need to think about policy

我们要重新考虑政策

and what kind of policies might be effective.

哪一种政策会更有效

And a great way to learn about policy is to look at what worked in the past.

看看过去哪些政策有效能极大帮住我们

The reason that we know that the ABC campaign

我们知道ABC准则在乌干达有效

was effective in Uganda is we have good data on prevalence over time.

是因为我们有过去的数据来佐证

In Uganda we see the prevalence went down.

我们知道在乌干达传播极大的减弱

We know they had this campaign. That's how we learn about what works.

而他们有实施了这个运动 所以我们得出它有效的结论

It's not the only place we had any interventions.

这不是我们有介入的唯一地区

Other places have tried things, so why don't we look at those places

别的地方也实施了政策 为什么我们不同样看看这些地方

and see what happened to their prevalence?

看看他们的传播率是否变化了

Unfortunately, there's almost no good data

不幸的是，在非洲截止2003年关于艾滋病传播的

on HIV prevalence in the general population in Africa until about 2003.

在整体人口上的数据再也没有了

So if I asked you, "Why don't you go and find me

如果我问你 为什么不告诉我

the prevalence in Burkina Faso in 1991?"

在布基纳法索1991年传播率是多少

You get on Google, you Google, and you find,

你上了谷歌 却发现

actually the only people tested in Burkina Faso in 1991

在布基纳法索1991年受测试的人

are STD patients and pregnant women,

只有性病患者和孕妇

which is not a terribly representative group of people.

这并不是极具代表性的一个人群

Then if you poked a little more, you looked a little more at what was going on,

如果你再深入一点 你就会发现更多

you'd find that actually that was a pretty good year,

你会发现当年情况很好

because in some years the only people tested are IV drug users.

因为在那几年被测试者只有静脉吸毒者

But even worse -- some years it's only IV drug users,

实际上情况更糟 几年只有静脉吸毒者

some years it's only pregnant women.

几年只有孕妇

We have no way to figure out what happened over time.

我们无法得知那几年到底发生了什么

We have no consistent testing.

我们没有前后一致的测试

Now in the last few years, we actually have done some good testing.

在最后几年 我们确实做了一些比较好的测试

In Kenya, in Zambia, and a bunch of countries,

在肯尼亚 在赞比亚 和一些国家

there's been testing in random samples of the population.

这些测试都是在人口中随机进行的

But this leaves us with a big gap in our knowledge.

但它却在我们的认知里留下一个巨大的鸿沟

So I can tell you what the prevalence was in Kenya in 2003,

我能告诉你在肯尼亚2003年的感染情况

but I can't tell you anything about 1993 or 1983.

但我不能告诉你关于1993年到1983年的任何情况

So this is a problem for policy. It was a problem for my research.

现在的政策有问题 我过去的研究也有问题

And I started thinking about how else might we figure out

我开始思考我们能不能得到别的什么

what the prevalence of HIV was in Africa in the past.

关于过去非洲艾滋病的感染情况

And I think that the answer is, we can look at mortality data,

结论是我们分析死亡率

and we can use mortality data to figure out what the prevalence was in the past.

用死亡率来估算艾滋病的感染率

To do this, we're going to have to rely on the fact

要完成这个 我们要建立在

that AIDS is a very specific kind of disease.

艾滋病是一种非常特殊的疾病的事实上

It kills people in the prime of their lives.

它在人们年轻的时候置人于死地

Not a lot of other diseases have that profile. And you can see here --

并没有太多其他的疾病也像这样 你可以看到

this is a graph of death rates by age in Botswana and Egypt.

这是一个以年龄划分关于在博茨瓦那和埃及的人口死亡率的图表

Botswana is a place with a lot of AIDS,

博茨瓦纳是一个艾滋病疫情严重的地方

Egypt is a place without a lot of AIDS.

埃及是一个没有太多艾滋病患者的地方

And you see they have pretty similar death rates among young kids and old people.

它们有着在儿童和老年人群中相似的死亡率

That suggests it's pretty similar levels of development.

这说明他们有着相似的发展水平

But in this middle region, between 20 and 45,

但在中间层 在20到45岁间

the death rates in Botswana are much, much, much higher than in Egypt.

在博茨瓦纳的死亡率要远高于在埃及的

But since there are very few other diseases that kill people,

又由于少有其他的致命性疾病

we can really attribute that mortality to HIV.

这种死亡率只能是由艾滋病导致的

But because people who died this year of AIDS got it a few years ago,

但又由于当年死于艾滋病的是在几年前就得病的

we can use this data on mortality to figure out what HIV prevalence was in the past.

我们就可以用这些数据来了解过去艾滋病的感染情况

So it turns out, if you use this technique,

结果是如果你用这种方法

actually your estimates of prevalence are very close

你所估算的感病率将会与

to what we get from testing random samples in the population,

我们随机抽样所得的结果很相近

but they're very, very different than what UNAIDS tells us the prevalences are.

却与联合国艾滋病联合工作组提供的数据大相径庭

So this is a graph of prevalence estimated by UNAIDS,

这是一个由联合国艾滋病联合工作组统计的感病数据

and prevalence based on the mortality data

另外一个是用死亡率估测出来的

for the years in the late 1990s in nine countries in Africa.

在九十年代末非洲十九个国家中的感染率数据

You can see, almost without exception,

几乎毫无例外的

the UNAIDS estimates are much higher than the mortality-based estimates.

联合国艾滋病联合工作组的测算数据远高于这一组

UNAIDS tell us that the HIV rate in Zambia is 20 percent,

联合国艾滋病联合工作组说在赞比亚艾滋病感染率是百分之20

and mortality estimates suggest it's only about 5 percent.

但用死亡率估测的确只有百分之5

And these are not trivial differences in mortality rates.

这在死亡率中绝不是微小的差距

So this is another way to see this.

从另一个角度来看

You can see that for the prevalence to be as high as UNAIDS says,

如果感染率真有联合国艾滋病联合工作组说的那么高的话

we have to really see 60 deaths per 10,000

我们应该看到在这个年龄层中

rather than 20 deaths per 10,000 in this age group.

半分之0.6的死亡率 而不是百分之0.2

I'm going to talk a little bit in a minute

我想花一点时间来谈一下

about how we can use this kind of information to learn something

我们怎么用这种信息来了解事物

that's going to help us think about the world.

这将会有助于我们了解世界

But this also tells us that one of these facts

但它同样也说明了

that I mentioned in the beginning may not be quite right.

我在开始提到的一些事实并不正确

If you think that 25 million people are infected,

如果你认为2500万人感染了

if you think that the UNAIDS numbers are much too high,

如果你认为联合国艾滋病联合工作组的数据太高了

maybe that's more like 10 or 15 million.

或许应该是1000到1500万人

It doesn't mean that AIDS isn't a problem. It's a gigantic problem.

这却不意味着艾滋病不是一个问题 这绝对是个大问题

But it does suggest that that number might be a little big.

只是之前的数据有些过大

What I really want to do, is I want to use this new data

我真正想做的是用这些新数据

to try to figure out what makes the HIV epidemic grow faster or slower.

去找到是什么影响了艾滋病传播的增长快慢

And I said in the beginning, I wasn't going to tell you about exports.

我在开始说 我不会谈什么进口之类的事

When I started working on these projects,

我在开始研究这些项目时

I was not thinking at all about economics,

并不是全想的跟经济学有关的东西

but eventually it kind of sucks you back in.

但事实上它会将你引导回去

So I am going to talk about exports and prices.

我要讲一些跟出口和价格有关的东西

And I want to talk about the relationship between economic activity,

我想谈一下经济活动

in particular export volume, and HIV infections.

特别是出口量和艾滋病传染之间的关系

So obviously, as an economist, I'm deeply familiar

很明显我作为一个经济学家 我更加熟悉

with the fact that development, that openness to trade,

对外贸易的发展和开放

is really good for developing countries.

将会给发展中国家带来极大的好处

It's good for improving people's lives.

这有助于改善民生

But openness and inter-connectedness, it comes with a cost

但开放和全球联系 是会有成本的

when we think about disease. I don't think this should be a surprise.

一旦和疾病联系起来 我觉得大家不应该吃惊

On Wednesday, I learned from Laurie Garrett

在周三 劳里·加勒特跟我说

that I'm definitely going to get the bird flu,

我肯定会得禽流感的

and I wouldn't be at all worried about that

但我丝毫不用担心

if we never had any contact with Asia.

只要我和亚洲走的不近

And HIV is actually particularly closely linked to transit.

艾滋病与过境的联系很紧密

The epidemic was introduced to the US

这个传染病

by actually one male steward on an airline flight,

是由一个在航班上的男管理员带来美国的

who got the disease in Africa and brought it back.

他在非洲染了病 然后就带了回来

And that was the genesis of the entire epidemic in the US.

这是艾滋病在美国传播的起源

In Africa, epidemiologists have noted for a long time

在非洲 流行病学家早注意到

that truck drivers and migrants are more likely to be infected than other people.

卡车司机和移民比其他人群更易感染

Areas with a lot of economic activity --

在那些经济活动较多

with a lot of roads, with a lot of urbanization --

公路较多 城市化更快的地方

those areas have higher prevalence than others.

比其他的地方流行强度更大

But that actually doesn't mean at all

事实上这并不意味着什么

that if we gave people more exports, more trade, that that would increase prevalence.

如果出口扩大，贸易加强，它就会增加传播度

By using this new data, using this information about prevalence over time,

在使用了新数据 使用了跨时段的传播度信息后

we can actually test that. And so it seems to be --

我就能真正地检测它 那么这意味着

fortunately, I think -- it seems to be the case

很幸运的是就我看来

that these things are positively related.

这些事件是正相关的

More exports means more AIDS. And that effect is really big.

出口越多意味着艾滋病患者越多 而且这种影响是巨大的

So the data that I have suggests that if you double export volume,

我研究的数据表明如果出口量扩大两倍

it will lead to a quadrupling of new HIV infections.

会导致艾滋病感染病例数扩大四倍

So this has important implications both for forecasting and for policy.

这对于预测和政策都有重要的影响

From a forecasting perspective, if we know where trade is likely to change,

从预测的角度 如果我们知道何处贸易将发生变化

for example, because of the African Growth and Opportunities Act

比方说因为非洲增长与机遇法案

or other policies that encourage trade,

或其他鼓励贸易的政策出台

we can actually think about which areas are likely to be heavily infected with HIV.

我们可以想见哪些地方将受到艾滋病的侵袭

And we can go and we can try to have pre-emptive preventive measures there.

我们就可去那里 采取先发制人的预防措施

Likewise, as we're developing policies to try to encourage exports,

同样地 如果我们要出台鼓励出口的政策

if we know there's this externality --

我们知道有这样一种外部性

this extra thing that's going to happen as we increase exports --

因为我们增加出口所带来的其他事情的变化

we can think about what the right kinds of policies are.

我们就可以更好的制定政策

But it also tells us something about one of these things that we think that we know.

它同样也说明了一些我们觉得我们了解的事情

Even though it is the case that poverty is linked to AIDS,

尽管艾滋病是和贫困紧密相连

in the sense that Africa is poor and they have a lot of AIDS,

而且非洲很穷 他们那也有很多艾滋病患者

it's not necessarily the case that improving poverty -- at least in the short run,

但改变贫穷的现状也不是必须的 至少在短期不是

that improving exports and improving development --

加大出口和扩大发展

it's not necessarily the case that that's going to lead

也并不一定能够

to a decline in HIV prevalence.

减轻艾滋病的传播

So throughout this talk I've mentioned a few times

至始至终我提到过几次

the special case of Uganda, and the fact that

乌干达的特殊案例

it's the only country in sub-Saharan Africa with successful prevention.

它是唯一一个在撒哈拉以南的非洲国家里的成功预防案例

It's been widely heralded.

它广为人知

It's been replicated in Kenya, and Tanzania, and South Africa and many other places.

在肯尼亚、坦桑尼亚、南非以及很多地方被复制使用

But now I want to actually also question that.

我现在真正想置疑的是

Because it is true that there was a decline in prevalence

因为在九十年代在乌干达

in Uganda in the 1990s. It's true that they had an education campaign.

传播率确实下降了 他们也确实采取的是教育运动

But there was actually something else that happened in Uganda in this period.

但在那个时期在乌干达还发生了一些别的事

There was a big decline in coffee prices.

在咖啡价格上有很大的下降

Coffee is Uganda's major export.

咖啡是乌干达的主要出口产品

Their exports went down a lot in the early 1990s -- and actually that decline lines up

在九十年代早期他们出口量大幅下降 而这种降幅的变化

really, really closely with this decline in new HIV infections.

这和新感染艾滋病数的降幅极度接近

So you can see that both of these series --

你们可看到这些

the black line is export value, the red line is new HIV infections --

黑线是出口值 红线是新感染艾滋病数

you can see they're both increasing.

你发现它们都增长了

Starting about 1987 they're both going down a lot.

从1987年起 它们又都开始大幅下降

And then actually they track each other

它们的轨迹在年代末的增加变化上

a little bit on the increase later in the decade.

又有一些重叠

So if you combine the intuition in this figure

将你的直觉和

with some of the data that I talked about before,

我之前讲的一些数据联系起来

it suggests that somewhere between 25 percent and 50 percent

则发现大约有百分之25到50的

of the decline in prevalence in Uganda

在乌干达的传播减少比率

actually would have happened even without any education campaign.

是在没有任何教育运动的情况下也会发生的

But that's enormously important for policy.

这对于制定政策极度重要

We're spending so much money to try to replicate this campaign.

我们花了大量的钱试图复制这项运动

And if it was only 50 percent as effective as we think that it was,

但如果仅仅只有我们预想的效果的一半的话

then there are all sorts of other things

我们何不把我们的钱投在

maybe we should be spending our money on instead.

一些其他的事上呢

Trying to change transmission rates by treating other sexually transmitted diseases.

通过应对其他性传播疾病来试图改变传播速度

Trying to change them by engaging in male circumcision.

通过包皮环切术来改变他们

There are tons of other things that we should think about doing.

有数以万计的事我们还可以做

And maybe this tells us that we should be thinking more about those things.

我们或许应该多考虑一下这些方面的事

I hope that in the last 16 minutes I've told you something that you didn't know about AIDS,

希望在刚刚的16分钟我告诉了大家一些关于艾滋病不为人知的信息

and I hope that I've gotten you questioning a little bit

希望我引起了大家对一些自己知道的事

some of the things that you did know.

的一些疑问

And I hope that I've convinced you maybe

我希望我使你们相信或许

that it's important to understand things about the epidemic

为了制定政策

in order to think about policy.

去了解传染病的事情是很重要的

But more than anything, you know, I'm an academic.

但是你要知道 我是一个学者

And when I leave here, I'm going to go back

当我离开这 我会回到

and sit in my tiny office, and my computer, and my data.

我的小办公室里 对着我的电脑 我的数据

And the thing that's most exciting about that

和那些每一次我开始研究时

is every time I think about research, there are more questions.

就会出现的让我无比兴奋的新问题

There are more things that I think that I want to do.

我想要做的还要多得多

And what's really, really great about being here

能来这里真的非常非常棒

is I'm sure that the questions that you guys have

我确信你们思考的问题

are very, very different than the questions that I think up myself.

将会跟我自己想的截然不同

And I can't wait to hear about what they are.

我迫不及待地想知道它们

So thank you very much.

非常感谢大家。