Journal of Mathematical Finance, 2020, 10, 242-254 
https://www.scirp.org/journal/jmf 
ISSN Online: 2162-2442 
ISSN Print: 2162-2434 
 
 
 
Analyzing China’s Term Structure of Interest 
Rates Using VAR and Nelson-Siegel Model 
Minjie Ding 
Peking University, Beijing, China 
 
 
 
How to cite this paper: Ding, M.J. (2020) 
Analyzing  China’s  Term  Structure  of  In-
terest Rates Using VAR and Nelson-Siegel 
Model.  Journal of Mathematical Finance, 
10, 242-254. 
https://doi.org/10.4236/jmf.2020.102015 
 
Received: January 20, 2020 
Accepted: May 8, 2020 
Published: May 11, 2020 
 
Copyright © 2020 by author(s) and   
Scientific Research Publishing Inc. 
This work is licensed under the Creative 
Commons Attribution International   
License (CC BY 4.0). 
http://creativecommons.org/licenses/by/4.0/   
Open Access
 
 
Abstract 
China’s bonds market has developed rapidly in recent years. A further study 
of interest rate term structure is essential. Nelson-Siegel model is widely used 
to fit interest rate term structure around the world. In this essay, we try to 
find out whether Nelson-Siegel model is efficiency in China, and which mod-
el is most efficient among some typical variants of Nelson-Siegel model. After 
brief theoretical introduction, we conduct empirical analysis, which contains 
two  sections.  In  the  first  session,  we  focus  on  fitting  Chinese  interest  rate 
term structure using Nelson-Siegel model, and fitting efficiency turns out to 
be pretty good. In the  second section, we  establish a VAR model with ma-
croeconomic variables to predict parameters in Nelson-Siegel model, and use 
the combination of VAR and NS model to predict interest rate term structure 
in 2019 and 2020 respectively. Also, in terms of  prediction efficiency, VAR 
(Macro)-NS  model performs better than both VAR-NS  model without  ma-
croeconomic variables and simple NS model. 
 
Keywords 
China’s Term Structure, Nelson-Siegel Model 
 
1. Introduction 
Interest rate is one of most important variables in the financial market, which 
can depict the relationship between money supply and money demand. Treasury 
bonds are regarded as risk-free interest rate for high credit and low risk. Trea-
sury bond yield curve reflects the relationship between bond yield and term to 
maturity, so it is also known as interest rate term structure. Treasury bond yield 
curve  becomes  benchmark  for  financial  products,  and  it’s  critical  to  financial 
market. 
China’s treasury bond curve began to form since year 2002. Electronic trea-
 
DOI: 10.4236/jmf.2020.102015    May 11, 2020 
 
242 
Journal of Mathematical Finance 
M. J. Ding 
 
sury bonds were introduced in 2006, which increased the amount of treasury in-
vestment. By the end of 2019, total market value of China’s bond market reached 
97,060 billion RMB, yoy 13.2%, becoming the second largest bond market in the 
world. 
Scholars  and  investors  all  over  world  have  shown  great  interest  in  treasury 
bond yield curve, for its important role in financial market. Treasury bond yield 
curves in different countries present different characters. In China, interest rate 
used to be regulated, and it’s not easy to predict interest rate barely from market 
prospective. With the progress of interest rate marketization, does China’s trea-
sury bond yield curve becomes more easy to predict? Is the prediction convinc-
ing? This paper will focus on these questions in following discussion. 
This paper uses the method put up by Nelson & Siegel (1987), to fit treasury 
bond yield curve. This method is practical for few parameters, and each para-
meter has economic meanings. Also, this paper follows the research structure by 
Diebold & Li (2006). First, the paper fits China’s treasury bond yield curve using 
Nelson-Siegel  method  and  tests  its  efficiency.  After  that,  the  paper  establishes 
VAR  (vector  auto-regression  model)  to  predict  parameters  in  Nelson-Siegel 
model. Then, the paper gives the predicted treasury bond yield curve of 2020. 
Compared with relevant researches conducted by scholars and investor, this 
paper does some new work. First, the paper uses yield curve data from CCDC 
(China Central Depository & Clearing Co., Ltd.,   
http://www.ccdc.com.cn/ccdc/en/index.shtml)  as  raw  data,  while  other  re-
searchers usually use specific traded treasury bond in market. CCDC has already 
filtered market noise when CCDC calculates yield rate. Also, regulatory depart-
ment has assigned CCDC’s treasury bond yield curve as pricing benchmark. For 
example, China Banking Regulatory Commission requires commercial banks to 
use CCDC’s treasury bond yield rate as benchmark of risk management. Second, 
based on trade experience in Chinese bond market, the paper introduced several 
typical macroeconomic variables into dynamic Nelson-Siegel model, and estab-
lished  VAR(Macro)-NS  model.  Third,  in  order  to  test  the  efficiency  of 
VAR(Macro)-NS model, this paper introduces a VAR-NS model and a NS mod-
el. In addition, although there are already scholars around the world discussing 
the effect from macro variables on term structure, the importance of this topic is 
not  highlighted  in  China,  partly  because  of  long-term  regulated  interest  rate 
market and difficulty to get raw market data. This paper is first to fully exam ef-
fect from macro variables on term structure using most proper market data in 
China market. 
The remainder of this paper is as follows. Section 2 shows literature review of 
Nelson-Siegel model, including recent research done by Chinese scholars. Sec-
tion 3 gives brief introduction to Nelson-Siegel model. Section 4 describes how 
we estimate the level, slope and curvature factors of the yield curve, and we test 
whether  Nelson-Siegel  model  can  fit  Chinese  treasury  bond  yield  curve  well. 
Section 5 examines predictive ability and gives our predicted yield curve based 
243 
Journal of Mathematical Finance 
 
DOI: 10.4236/jmf.2020.102015 
 
M. J. Ding 
 
DOI: 10.4236/jmf.2020.102015 
 
 
on VAR(Macro)-NS model. 
2. Literature Review 
As scholars and investors use yield term structure more frequently, more relative 
models come up. 
Nelson-Siegel  model  was  first  proposed  by  Nelson  and  Siegel  (1987).  This 
model is widely favored, for its intuitive economic explanation, less parameters 
to estimate and good fitting performance. However, Nelson-Siegel model fails to 
produce a multi-peak yield curve. Svensson (1994) added an exponential poly-
nomial to solve the problem, and got Nelson-Siegel-Svensson model. Although 
Nelson-Siegel-Svensson model can generate a multi-peak yield curve, too many 
parameters makes it too sensitive to initial value. 
Nelson-Siegel  models  are  widely  used  both  by  academic  research  and  gov-
ernment policy. According to report from BIS (2005) [1], central banks of Bel-
gium, Finland, France, Italy and Span use Nelson-Siegel models to estimate yield 
term structure, and centrals banks of US, Canada, UK, German and Switzerland 
choose Nelson-Siegel-Svensson model. 
Dynamic Nelson-Siegel model was first set up by Diebold and Li (2006) [2]. 
They assumed that factors of NS model follow AR (1) process. Christensen, Di-
ebold and Rudebusch (2009) [3] consider no-arbitrage restriction in DNS model, 
which  is  called  AFDNS  model.  Koopman,  Malle  and  Van  (2010)  [4]  add 
GARCH process into DNS model. 
In China, Shen (2010) [5] applied DNS model to Chinese inter-bank market. 
Wang  (2010)  studied  no-arbitrage  DNS  model  and  found  the  slope  factor  has 
closer  correlation  with  macroeconomics  variables.  Shen  and  Shuai  (2017)  [6] 
decreased  parameter  numbers  in  Lengwiler  and  Lenz’s  (2010)  [7]  model,  they 
introduced  VARMA  (1,  1)  into  DNS  model  and  ensure  the  independence  of 
impulse from factors. 
In  addition,  many  scholars  and  investors  began  to  explore  the  relationship 
between interest rate and macroeconomic variables. 
Ang and Piazzesi (2003) [8] added macroeconomic variables to interest rate 
model.  They  got  a  better  predictability,  and  found  that  85%  of  yield  volatility 
could be explained by macroeconomic variables. Based on this work, Bikbov and 
Chernov (2010) [9] proposed a model without restrictions on the number of la-
tent variables. Also, discussion about forecast horizons came up, Hordahl (2006) 
and Moench (2008) [10] found model with macro variables had better forecast-
ing performance only for longer prediction horizons, while de Pooter (2010) and 
Altavilla  (2014)  outperformed  random  walk  benchmarks  only  for  short-term 
maturities  at  shorter  horizons.  Coroneo  (2016)  [11]  added  backward-looking 
macroeconomic variables into term structure model, and his model performed 
better than random walk forecasts from 3 to 24 months ahead. It is argued that 
macro variables is useful particularly in certain years, such as in recessionary pe-
riods. This argument is supported by evidence provided by Guidolin and Pedio’s 
244 
Journal of Mathematical Finance 
M. J. Ding 
 
(2019) [12], whose models with monetary policy variables significantly increased 
predictive ability during 2008 financial crisis. 
Interest rate in China was  partially regulated until recent years. As a result, 
Chinese  scholar  didn’t  pay  much  attention  to  macroeconomic  variables  and 
yield term  structure before  2010. In recent years, relevant studies came up,  as 
interest  rate  realized  liberalization.  Zeng  and  Niu  (2013)  became  first  Chinese 
scholar  who  got  term  structure  of  real  interest  rate  and  inflation  rate,  using 
no-arbitrage  models.  They  also  found  that  inflation  rate  affected  more  on 
short-term  yields,  while  real  interest  rate  affected  more  on  long-term  yields. 
Qiang and Hou (2018) [13] built an affine interest rate model based on bench-
mark interest rate, market liquidity and risk premium, which explained the term 
structure well. They found that benchmark interest rate is determinant to other 
term yields, and market liquidity influence more on short-term yields, while risk 
premium affects more on long-term yields. 
3. Brief Introduction to Nelson-Siegel Model 
In 1987, Nelson and Siegel first use Nelson-Siegel model to fit yield curve, and 
the model is as follows. 
y
( )
τ β β
2
=
+
1
∗
−
λτ
1 e
−
λτ
+
β
3
∗
−
λτ
1 e
−
λτ
−
λτ
−
e
                      (1) 
Diebold and Li said that yield rate should change with time, and put forward 
Dynamic Nelson-Siegel model, and the model is as follows. 
y
t
( )
τ β β
2
=
+
t
1
∗
t
λτ
−
1 e
−
λτ
+
β
t
3
∗
λτ
−
1 e
−
λτ
λτ
−
−
e
                    (2) 
In the formula above, t represents a specific time point.  τ  represents time to 
ty τ   represents the yield rate of a treasury bond with  τ  to matur-
( )
β β β   and  λ  are parameters to be estimate. 
maturity. 
ity at time t. 
•  As  τ  approaches  infinity,  we  get 
( )
τ β
t
1
y
lim t
→∞
τ
1tβ   is  regarded  as 
1tβ   will change the overall yield rate of a 
.  So 
=
t
1
,
,
2
horizontal parameter. Change of 
treasury bond. 
t
3
t
•  As  τ  approaches zero, we get 
y
−
t
( )
0
( )
0
β
t
1
β
2
y
t
y
t
−
=
=
t
get 
ter. 
( )
y
lim t
τ β β
2
0
τ
→
(
)
∞ .  So 
=
. After transposition, we 
2tβ   is  regarded  as  slope  parame-
+
t
1
t
•  When  τ  is  a  normal  number  around  60,  which  means  the  treasury  bond 
+
−
=
y
t
β
t
1
( )
0
0.5
y
t
)
60
(
=
has 5 years (60 months) to maturity, we approximately get   
(
y
∗
β
t
t
2
)
( )
β
−
τ
t
3
vature parameter. 
The right side of formula divides the yield rate into three parts. The first item 
1tβ , which affects long-term yield rate. We can call it long-term factor. The   
β
. After transposition, we get   
t
3
(
y
−
t
3tβ   is  usually  regarded  as  cur-
0.5
+
∗
(
( )
y
τ
t
)
∞ .  So 
)
is 
second item is 
 
DOI: 10.4236/jmf.2020.102015 
 
1 e λτ
−−
λτ
, when  τ  approaches infinity, this item approaches ze-
245 
Journal of Mathematical Finance 
M. J. Ding 
 
 
 
DOI: 10.4236/jmf.2020.102015 
 
 
ro, which means this item affect yield rate more in short term, as shown in Fig-
ure  1.  We  can  call  it  short-term  factor.  The  third  item  is 
λτ
−
1 e
−
λτ
λτ
−
−
e
,  as   
τ  approaches infinity or zero, the third item approaches zero, which means its 
effect  is  around  medium-term,  as  shown  in  Figure  2,  so  we  can  call  it  me-
dium-term factor. So all factors that affect yield curve can be divided into these 
three group, as shown in Figure 3. 
λ  is usually given previous to other work. On the one side,  λ  determines 
when 
λτ
−
1 e
−
λτ
λτ
−
−
e
  will reach largest value. On the other side,  λ  determines 
the speed 
1 e λτ
−−
λτ
  decreases with time. Diebold and Li (2006) take 
λ=
0.0609
, 
which means medium factor reaches largest in 30th month. 
Figure 1.  1 e λτ
−−
λτ
  trend (assuming 
0.1λ=
). 
 
 
Figure 2.  1 e
−
λτ
−
λτ
−
λτ
−
e
  trend (assuming 
0.1λ=
). 
246 
Journal of Mathematical Finance 
M. J. Ding 
 
Figure 3. Deposition of factors that affect yield rate. 
4. Can Nelson-Siegel Model Fit Chinese Treasury Bond Yield 
Curve Well? 
 
4.1. Search for Best Value of λ 
Considering  that  λ  has  an  influence  on  the  fitting  effect,  we  should  first 
choose an optimal  λ. Here we take this method. The first step is choose a cer-
tain  λ, then we calculate 
β β β   base on this given  λ. After that, we use 
t
1
β β β   to get fitting value and their estimation error. By now, we get an es-
t
1
timation error, based on a given  λ. Now, we tried each  λ  between 0.005 and 
0.070, with interval of 0.001. 
,
,
,
,
2
3
2
3
t
t
t
t
We take 204 monthly treasury bond yield curve from year 2002 to year 2018 
as our sample. Also, considering that bonds with more than 10 years to maturity 
may have deviation because of lack of liquidity, we choose bonds whose term to 
maturity is between 1 month and 10 years. 
After all 65 trials, we find that, the estimation error is least when  λ  is 0.030, 
which  means the  medium factor become largest in  around 4th  and  5th year, as 
shown in Figure 4. 
t
t
2
,
,
β β β   for  each  month  and  average 
t
1
4.2. Fitting Effect of Nelson-Siegel Model on Chinese Treasury Bond 
We take 204 monthly treasury bond yield curve from year 2002 to year 2018 as 
our raw data. Firstly, we use Nelson-Siegel model to do monthly regression, and 
get 
β β β   during  the  sample 
t
1
period. Then we use the average 
β β β   to get predicted yield rate for each 
t
1
maturity, and compare them with real yield rate. The table below shows the re-
sult. As we can see in  Table 1, the prediction error is all between 0 ~  5 basis 
point, which demonstrate that Nelson-Siegel model can give an excellent predic-
tion on Chinese treasury bond yield curve. 
,
,
,
,
2
3
3
2
t
t
t
3
t
4.3. Test of Meaning of Parameters 
As  we  discussed  above, 
1tβ   represents  horizontal  parameter, 
2tβ   represents 
247 
Journal of Mathematical Finance 
 
DOI: 10.4236/jmf.2020.102015 
 
M. J. Ding 
 
 
slope  parameter  and 
3tβ   represents  curvature  parameter  in  Nelson-Siegel 
model. While in real trading market, we can use yield rate of bonds with 10 year 
to maturity to represent horizontal level of yield curve. Also, real slope is often 
approximately  calculated  by  substracting  1-year  yield  rate  from  10-year  yield 
rate.  Moreover,  we  can  use  “(10-year  yield  rate  -  10-year  yield  rate)  -  (5-year 
yield  rate  -  1-year  yield  rate)”  to  approximately  represent  real  curvature.  Our 
calculation result is in Table 2. We find that the correlation between 
1tβ   and 
real  horizontal  level  is  0.866,  the  correlation  between 
2tβ   and  real  slope  is 
−0.964 and the correlation between 
3tβ   and real curvature −0.554. These three 
parameters all have close relationship with real observed values. Figure 5, Fig-
ure  6  and  Figure  7  show  the  trends  of  three  relationships  mentioned  above, 
which further manifest the close correlation. 
 
Table 1. Real yield rate vs. fitted yield rate in 2002-2018. 
 
Figure 4. Average absolute fitting error from Nelson-Siegel model with different λ. 
2 
3 
6 
9 
12 
24 
36 
48 
60 
72 
84 
96 
108 
120 
2.3806  2.4132  2.4810  2.5256  2.5745  2.7624  2.9253  3.0673  3.1769  3.3090  3.3960  3.4719  3.5313  3.5837 
2.3767  2.3952  2.4498  2.5030  2.5547  2.7470  2.9166  3.0650  3.1941  3.3063  3.4037  3.4882  3.5617  3.6258 
−0.38  −1.80  −3.12  −2.26  −1.98  −1.54  −0.87  −0.23 
4.21 
−0.27 
1.73 
0.77 
1.63 
3.05 
Time to maturity τ (month) 
Average historical yield rate 
(%) 
Fitted yield rate (%) 
Predicted error (BP) 
 
 
DOI: 10.4236/jmf.2020.102015 
 
Table 2. Correlation between estimated parameters and real term structure. 
Observed height   
of yield curve 
Observed slope   
of yield curve 
Observed curvature of yield curve 
Yield rate (10) 
Yield rate (10) minus 
yield rate (1) 
Yield rate (10) plus yield rate (1), minus 
two times yield rate (5) 
0.866 
−0.074 
0.341 
0.398 
−0.964 
0.031 
−0.010 
0.147 
−0.554 
 
 
1tβ  
2tβ  
3tβ  
Note: Yield rate (x) means the yield rate of treasury bond with x years to maturity. 
248 
Journal of Mathematical Finance 
Note: Yield rate (10) mean the yield rate of treasury bond with 10 years to maturity. 
Figure 5. Trends of 
1tβ   and yield rate (10). 
M. J. Ding 
 
 
 
Note: Slope of yield curve observed is approximately calculate by yield rate of 10-year treasury bond 
minus that of 1-year treasury bond, that is yield rate (10)-yield rate (1). 
Figure 6. Trends of − 2tβ   and real slope of yield curve. 
 
 
 
Note: Curvature of yield curve is approximately calculate by yield rate of 10-year treasury bond mi-
nus plus that of 1 year treasury bond, subtracted by two time yield rate of 5-year treasury bond, that 
is yield rate (10) + yield rate (1)-2 * yield rate(5). 
Figure 7. Trends of − 3tβ   and real curvature of yield curve. 
249 
Journal of Mathematical Finance 
 
DOI: 10.4236/jmf.2020.102015