Introduction

Focusing mainly on structural design, my current role is to teach younger students basic mathematics including optimization, and to introduce graduate students and more senior students to the concepts of safety and reliability, teach them how these are reflected in the creation of design rules, explain how to interpret issues that emerge in society, and so on.

My current area of specialization is connected to the idea which I had when I was a high school student that public things have a high value, and to the fact that I was stimulated by the words of Isaiah Ben-Dasan when he said that the Japanese consider water and security to be free. During the boom in the theory of justice two years ago, I also felt that civil engineers (many of them are simple adherents to the theory of the greatest happiness for the greatest number of people) should be brought into the discussion. Then last year's disaster occurred. There are many technical issues that should be discussed separately, but I am more eager to talk about the fundamental social aspects. There seems to be a common structure of interlinked issues such as debates on the meaning of public work and project screening, or the discussion and an international comparison of the standards of security required by societies, which is included among TPP issues.

A civilized society is one in which people's lives are encircled by a given outer wall, so to speak, of guarantees for their convenience and security, and inside which the fruits of economic activities are shared out and the pursuit of happiness discussed (I feel that Prof. Sandel, too, sometimes seems to lean away from skepticism about the self-evidence of an outer wall). The outer wall in this case can be easily understood to mean Tohoku's coastal breakwaters (which are actual walls), the roads that carried people and supplies to help the victims, and the electricity supply to areas including the Kanto region.

How can we discuss justice with the people on the inside of the outer wall from the perspective of the wall? In economics, there is a concept of welfare for converting monetary value into things like a sense of happiness or satisfaction, but doesn't justice also include a measuring scale to enable big and small comparisons? Whether this resembles the ideas I have set out below is something I would like to know.

You cannot see the outer wall unless you try

I frequently throw the title question about rice fields at my high school pupils and university freshmen. Of course there is not only one correct answer. The growth of life is achieved by giving certain autonomy to elements that exist in the rice field, such as soil and water, air and sunlight, and microorganisms, so it would be understandable to answer that they are natural. And yet there are no rice fields created by the hand of nature, and although a rice field nurtures life, it cannot sustain animals such as monkeys or wild boars. A rice field is also artificial in the sense that human beings restrict the life that it is able to nurture. Our perspective is to take things one step further and seek the artificialness of rice fields. How to handle waste land, swamps or forests, where to bring water from, how to arrange footpaths, how to harden the ground. The spread of hydroponics for growing rice in Japan is thought to date from the Yayoi period, and to the people of that time a rice field must have seemed like an advanced structure. The fact that it looks natural is a consequence of our creation of an outer wall. This is the message I venture to convey to people taking their first look at this subject.

These days, people focus on the impact (in a negative sense) on the agricultural environment or on sustainability. That's fine, but all I hear is people from two extremes, either talking about the "beautiful natural environment" or complaining of "environmental destruction and health hazards." I feel they should calm down a little.

Would it be stretching the argument to consider rice fields in the same way as electricity (power supply)? No one thinks of electricity as being natural, but isn't the way we take it for granted and don't know how it is supplied rather like the way we are unaware of the artificialness of rice fields? The focus of criticism on their negative aspects is similar, too. I think the water supply is the same; the tea in the plastic bottle in front of you which you take for granted is rain that fell somewhere, sometime.

What do you get if you multiply zero by infinity?

We are at the mercy of nature, but some people assume that artificial things can always be controlled. Engineers consider accidents to be an inevitability accompanying the actions of ordinary people (no one obtains a driving license with the intention of causing an accident). Even though we cannot avoid accidents, we should reduce the risk, and to find the point of compromise, the following equation (or rather our thinking process) can be used:

Minimize C_T = C_I + P_F x C_F . (A)

C_I on the right side is the initial cost, P_F is the probability of failure, and C_F is the cost of failure. The anticipation value expressed by the product of the latter two is the correct definition of the term risk. I stands for initial and F for failure. Although it is common practice in our field to write it in the form of the whole cost, it could be easier to understand if we wrote the incremental form (⊿P_F, ⊿C_F＜0) lowering the existing risk by additional cost investment in an existing asset (⊿C_I＞0), such as in earthquake reinforcement work on a house, for example, and explained the meaning of a cost-benefit analysis comparing the reduction value in the second phrase with the first phrase. There is nothing special about this equation. It appears in risk management, insurance, and lotteries (where F should be changed to success. In a lottery, however, we are purchasing a dream or fantasy rather than the prize-money anticipation value) and the valuation of risk assets is also essentially the same thing. We can also use this perspective to explain things such as the difference in beef distribution standards in Japan and the US (Japan is keen to reduce the P_F of mad cow disease, for which it requires a large C_I). The question of who is paying the cost is also included.

If we try to explain that in the area of an outer wall we apply the thought process of this unremarkable equation, communication with the recipient suddenly becomes difficult. The value of social stability and human life is limitless, which means C_F is infinity. And of course people should not be exposed to danger, so P_F must be zero. There is no mistake here, but we will receive no answer if we ask how much money we can use. That is C_I in the above equation. Previously, people said "we'll leave it to you," but criticism of wastefulness eventually led to such amounts being assessed by public project screening. Of course people take offence at lack of diligence in screening, but many experts, too, should reflect on their own behavior, as I don't think they have sorted out the points at issue sufficiently and expressed themselves well enough for people to be able to understand what is being said (My colleague Tadashi Yamada's lectures to Seiji Maehara almost every week while the latter was Minister of Land, Infrastructure, Transport and Tourism are still fresh in our minds). I do not think that it is right to make everything high spec (including beef). Excessive demand for an exceedingly small P_F that does not match people's ability to pay is a trade off that augments the P_F of the separate C_F of financial collapse.

In relation to P_F, there is also the argument that zero differs from infinity. Different people's level of understanding of this varies, but I think that today people have become more likely than before to accept the explanation that since long ago there has never been 100% security. There is also the issue of people's intuitive understanding of the complexity of calculation methods and the meaning of probability. And there is the free rider problem because of the difference between who bears the cost and who receives the benefits.

Recently, however, I feel the need for a sort of common language for exchanging opinions, especially between engineers and the public, who are the beneficiaries, as a way of assessing C_I and C_F. As I mentioned at the beginning, how can we incorporate welfare, which includes not only concrete financial spending but also subjective factors? That is what I meant by a scale for measuring justice. To give just one specific example, when the Tohoku coastline is restored, how high should the breakwaters be made? If told to cope with the biggest anticipated tsunami (P_F = 0), an engineer will provide an answer accordingly. But is that OK? Aside from the financial impact, will people be happy being separated from the sea by a high concrete wall, for instance? Isn't that a part of C_I? (This may be the sorrow of realizing that rice fields are not natural.)

Taking stewardship

In the medical field, for example, things have changed from the days when doctors dictated in the selection of treatment strategy to the current era of greater respect for patients' right to self-determination and an increase in presentation of second opinions. Not only doctors but all experts, including engineers, must follow the principle of changing from mastership to stewardship. We engineers should use words differently to explain ourselves better, and take the attitude of letting people consider a number of possible ideas rather than just saying things like "Leave it to us" or "Amateurs should keep quiet." This will probably require various kinds of preparation, such as understanding the importance of the outer wall (which could also be called modestly a substructure), being aware that rice fields are not natural (security is not free), and explaining the content of zero and infinity.