Preface
Various kinds of incidents occurred more frequently in recent years. The 911 incident
happened in 2001 was one of the social security incidents while "SARS" appeared
in 2003 was attributed to the public health incident triggered by bacteria. There
were other kinds of emergency that had made great tragedy on human beings such as
the power blackouts in August
2003
in
North America and tsunami natural disasters on Indian Ocean in 2005(Ji Lei, etc.
2006). Although the probability of all these incidents is very small, the influence
is tremendous. For example on 26 December 2004 the Indian Ocean tsunami killed in
excess of 225,000 people and dislocated millions more in countries spread around
the Oceans rim from Kenya to Indonesia. The 2001 bombing of the
World
Trade
Center
in
New York
generated direct and indirect losses that most probably will exceed 50 billion US
Dollars. Emergency incidents have become an important restricting factor for economic
and social development.
There is increasing recognition of the need for study of emergency management. Some
of the EM research relates to social sciences (Hughes, 1991). This type of research
focuses on disaster results, sociological impacts on communities, psychological
effects on survivors and rescue teams, and organizational design and communication
problems (Li Jie,2005; C. S. ReVelle, H,2005;Swersey 1994, Sherali,1997). van Wassenhove
wrote six cases on Humanitarian Logistics in Disaster Situations, commenting that
"the subject of disaster management is an absolutely fascinating one that is growing
in importance" (Van Wassenhove,2003). Green and McGinnis (2002) provide a discussion
of the broad classification of these events by causation that helped frame our investigation.
Others experts also gave details on classification of emergency in incidents management
(Jean Luc Wybo, Harriet Lonka, 2002; Yang Jing, 2005; Eleftherios Iakovou, Christos
Douligeris, 2001).
In reality, many countries and cities have established emergency response mechanism.
USA
established its Federal Emergency Management Agency (FEMA) in April 1979 which should
be one of the earliest in the world. Many other countries also established related
organizations and systems on emergency management, including
Russia
,
Japan
,
South
Korea
,
China
, etc.
The Chinese government devotes great attention to disaster reduction and has achieved
significant results. The Ministry of Civil Affairs of China assumes the work of
organizing and coordinating emergency relief, supervising and promulgating information
on disasters, managing and distributing disaster relief funds and central government
materials and monitoring their use. The Ministry divides the work of responding
to unexpected natural disasters into three grades based on the scene of disaster
losses, and enacted the "Work rules for response to unexpected natural disasters
of the Ministry of Civil Affairs of China" in June2003.
China
has promulgated laws such as the "Law on Flood Control of P. R. China" and "Law
on Earthquake Control and Disaster Reduction of P. R. China"
Media has also played an important role as a social force except the government.
Confronted with emergency, it's very important for the government to let the public
correctly understand the current conditions and guide them to create a conductive
atmosphere for solution to the incident through media. Therefore, media are indispensable
in the process of emergency management. For example, during the early stage of SARS
crisis, the medias of our country just try to deal with crises by attempting to
prevent disclosure of uncomfortable facts. And this accelerates the spread of the
diseases to some extent. In the critical time that the SARS crisis transformed from
incubation to outbreak, however, all the medias changed their strategies and rush
on the diseases information afterwards. Unfortunately the role of medias in the
crises was very limited with lack of relative independence and failed to take the
initiative to cooperate with the crisis management of government. In contrast, when
the 9.11 incident broke, the medias delivers all kinds of news to audiences and
guide them to act rationally, avoiding rumors spread effectively. Apart from discuss
such problems about who was the terrorists and what actions the government would
take, American media put their emphases on appealing the public to resume normal
life as much as possible. Some newspapers even call on the public to refuel, shopping
and spending. On the other hand, the over exposed scene of terrorists or slaughter
about the 9.11 incident may result in panic. In one word, the news media plays an
essential role in emergency management, but surveys indicate that the media is widely
viewed as biased (Baron, David ,1845).
In our country the media always focus on positive publicity propaganda because of
media constrain, and try to avoid to disclosure bad incidents because of strict
control of the press. Is that effective to put medias in competitive market? In
this paper we will discuss the factor of reducing media bias.
Model Description and Analyses
Players: The players in our model are "media" and "audiences". The "media"
may be the single organization in monopoly, or two corporations in competitive market,
and "audience" is the potential reader of media.
Actions: "media" responses for emergency and announces its bias strategy
s(d) and the price P it charges. Potential readers decide whether to buy the paper
with the price P according to his belief.
Information: The media get some information about emergency incident. Because
of the incomplete information and the constant variety, the media need to make some
judgment by maximizing his expected utility.
3.1. Reader's Utility Function
Readers are interested in some underlying variable t which might come from their
experience, knowledge education or previous news which is distributed N(0, vt).
Let p = 1/vt denote the precision. Readers hold a belief about t that
may be biased; beliefs are distributed N(b, vt). We assume that a rational
reader's utility is decreasing with the amount of slanting. So, if he reads a newspaper,
his utility is:
Ur
= ui*(d)− Xs2 − P
where P is the paper's price. If he does not read the newspaper, he gets utility
0.
Biased readers on the other hand get disutility from reading news inconsistent with
their beliefs.
The distance between the news and the reader's beliefs, b, was measured as (n −
b)2. The overall utility of a biased reader is:
(1)
U= ui*(d) − Xs2 −δ(n − b)2−
P.
where δ> 0 denote his preference for hearing confirming news, ui*
(d)is the average function of i.
We consider two different distributions of reader beliefs, homogeneous and heterogeneous.
Homogeneity means that all readers hold the same beliefs b. For example, all or
nearly all Chinese believe that
Taiwan
is an indiscerptible part of
China
. Heterogeneity means that there is a distribution of reader beliefs. We assume
that heterogeneous beliefs are distributed uniformly between b1 and
b2 where b1 < b2, and b2>0. We denote by b* the average of b1 and
b2.
In the homogeneous case, there is only one kind of reader. Bias is defined as the
average amount by which the news read deviates from the data for the average reader,
so we define Bhom = Ed[(n − d)2] to measures the
average bias that readers encounter, where n is the news read by these readers.
In the heterogeneous case, let ni be the news read by reader i∈[1, 2].
Bias is then denoted as:
Bhet = ∫i Ed[(ni − d)2].
3.2. Media's Strategy
Medias are in the business of reporting news about t. They receive some data d =
t +ε. In the above example, these data might be the death number and the suspect
SARE case. We assume that the medias then report these data with a slant s, so the
reported news is n = d+s(d). Before seeing the data d, media announces its slanting
strategy s(d) and the price P it charges. The media's utility function is (P-C)D,
where D is the demand of readers. Potential readers decide whether to buy the paper
with the price P. Once readers decide whether to buy the paper, the medias observes
its signal d and reports n = d+s(d). Readers read the news and receive their utility.
3.3. Equilibrium in Monopoly market
Here we consider the equilibrium in two conditions. One is in monopolized market
and the other is in competitive market. In the first condition we suppose there
is a single media, and there are two medias in the second condition.
3.3.1. Confronted with homogeneous readers
Confronted with homogeneous readers, the media's can extract all surpluses in monopolized
market. He maximizes expected utility:
max [ui*(d) − Xs2 −δ(n − b)2− C]=max u* −X ∫d(s*(d)2)
−δ ∫d(d + s*(d) −b) 2-C
For a given d, differentiating with respect to s, then we can get:
Xs+δ(d+s-b-C)=0.
That is:
(2)
S*hom(d) =δ(b +C− d)/(X+δ)
Input the value of s to the expected utility, we get price P:
(3)
P*hom = u* −Xδ[b2 + vd] /(X+δ)
Then we can compute news he reports is:
n =δb/(X+δ)+Xd/(X+δ)
The reported news is a convex combination of bias and data, with weights given by
utility parameters.
In this case we say the monopolist "slants towards b".
3.3.2
Confronted with heterogeneous readers
When confronted with heterogeneous audiences, the media's must first decide which
one of the heterogeneous groups is its target audience when it comes to monopoly
market.
Suppose medias faces a completely heterogeneous audience with b* = 0. For b*= 0,
the monopolists profits equal to
(4)
Let Pm be the global maximum of this function. At this maximum we get
the boundary condition
(5)
So if b2 − b1 < 2Y, the media will monopoly the whole market. He can then get
maximum profits by setting a price equal to the utility of the boundary reader.
His price and strategy is:
(6)
s*het =δ(b − d)/(X+δ)= −δd /(X+δ)
(7)
P*het = u* −Xδvd /(X+δ) −δ2b2
If b2 −b1 > 2Y the monopolist chooses not to cover the market.
The media in monopoly market covers the market if the dispersion of reader beliefs
is small enough. If beliefs are distributed too far apart, readers on either extreme
will not read the paper.
3.4 Equilibrium in competitive market
We suppose there is two medias in competitive market and there are two different
distributions of reader beliefs, homogeneous and heterogeneous.
3.4.1
Confronted with homogeneous readers
Case 1 In the competitive market, there are two medias confronted with homogeneous
audiences. First we consider the price-setting stage with audiences is homogeneous.
Let Vj be the reader's utility associated with reading news of media
j. suppose V1 > V2, the price equilibrium is for media
1 to charge V1 − V2 and capture the full market, and media
2 get zero. If V1 = V2, then both medias charge C. C
can be the fee for journalist or the opportunity cost for a reader to available
to the media.
In the competitive market, the strategy of each media is holding constant the rival's
strategy.
Any media's strategy is maximizing his expected utility:
max [ui*(d) − Xs2 −δ(n − b)2− C]
For both media, optimal strategy is:
(8)
S*hom(d) =δ((b +C− d)/(X+δ).
This shows that equilibrium is both medias provide equal utility, prices equal to
C.
They show that, when audiences have homogeneous biases, competition does not eliminate
them, it only leads to price reductions. Medias always cater to reader prejudices
no matter in monopoly market or in competitive market. This means that we cannot
get accuracy - even in the competitive media on information where the readers have
similar beliefs.
3.4.2
Confronted with heterogeneous readers
When confronted with heterogeneous readers, the media's must first decide which
one of the heterogeneous groups is its target audience in competitive market.
Firstly we calculate e the bias of the reader who is indifferent between reading
the two media if media j charges Pj and has bias zj . This allows us
to get the market share and the equilibrium price.
Secondly, we then calculate the best response functions for firms 1 and 2 respectively.
Suppose medias faces a completely heterogeneous audience with b* = 0 and we are
in a symmetric situation where z2 = - z1, b2 =
-b1. An audience with bias x receives utility:
u* −Xδ((vd+e2)/(X+δ) −δ2(zi− e)2/(X+δ)
−Pj
from reading paper j. If the reader with bias x is indifferent between these two
papers then their utilities are equal:
u* −Xδ(vd+e2)/(X+δ) −δ2(z2− e)2/(X+δ)
−P2= u* −Xδ((vd+e2)/(X+δ) −δ2(z1−
e)2/(X+δ) −P1
This equality can be simplified to:
(9) e= (z1+
z2)/2 + (P2−P1)X+δ/2 (z2− z1)δ2
Now we calculation best response price functions. Since the indifferent reader is
located at x firm profits are given by:
π1= (P1-C )(e-b1)/(b2-b1)
π2= (P2-C)(b2- e)/(b2-b1)
Differentiate profits with respect to each price; we can get medias' best price
response. For firm 1,
P1=P2/2 +(b2+z*)((z2− z1)δ2/(X+δ)+C
P2=(P1-C)/2 +(b2-z*)(z2− z1)δ2/(X+δ)
We get:
(10)
P1=2(b2+z*)((z2− z1)δ2/(X+δ)+3C/4
(11)
P2=(2b2− 2z*/3)((z2− z1)δ2/(X+δ)
The Nash equilibrium of market share can be calculated from the response functions:
e=z*/3-3C(X+δ)/8(b2+z*)(z2− z1)δ2.
Then we can calculate each medias' bias chosen by differentiating the profit function:
π1= P1(e-b1)
π2= P1(b2- e)
Differentiation with respect to z1 gives:
So Z1*=3C/8-b2
is bias equilibrium of media 1.Similarly bias equilibrium of media 2 is Z2*=
b2-3C/8
Therefore Z1*=
3C
/8-b2 and Z2*= b2-3C/8 is a Nash equilibrium.
Substitution the figure to profit function, prices must be equal to 4δ2b22/(X+δ).
Finally we verify that in equilibrium, the boundary conditions of the consumer are
satisfied. That is we must show that:
u* −Xδvd/(X+δ) −δ2(b2+3C/8)2/(X+δ)
− 6δ2b22/(X+δ)≥0
which equivalence to:
Now we get the medias choice in competitive market confronted with heterogeneous
readers:
If,
(12)
(13)
where without loss of generality we assume that firm 1 slants toward the left and
firm 2 slants toward the right. They share the whole market. The opportunity cost
C may affect the strategy of the media.
As in the standard Hotelling model, the media in monopoly market caters to both
audiences unless they are too far apart, while medias in competitive market positions
as differentiate from the other as possible and medias in monopoly market report
more diverse news than in competitive market when readers are heterogeneous.
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