1. Introduction
In the face of the worldwide spread of the coronavirus and the economic turmoil triggered by the global financial crisis, increased cross-border risk contagion has raised significant concerns regarding the macroeconomic effects of time-varying volatility shocks. Volatility shocks have the potential to spread across borders, impacting other countries through diverse channels, including global value chains, cross-border capital flows, and population movements [
1,
2,
3,
4,
5,
6]. This results in interconnected shifts in business cycles among nations. Mounting evidence suggests that financial integration plays a crucial role as a channel for transmitting international business cycles [
7,
8,
9,
10,
11,
12,
13,
14,
15,
16,
17,
18]. Although most of the studies focus on the level of shocks (e.g., productivity and financial shocks), little attention has been paid to the volatility of shocks. I argue that neglecting volatility shocks would underestimate the impact of financial integration on the comovement of business cycles across countries. Furthermore, a failure to address volatility shocks would reduce the precision of welfare analysis when evaluating financial integration.
In this paper, I study how financial integration affects the comovement of business cycles in the presence of volatility shocks. To conduct my analysis, I construct an international real business cycle (IRBC) model with a global bank, incorporating time-varying volatilities and recursive preferences. Drawing inspiration from Fernández-Villaverde and Rubio-Ramírez [
19] and Fernández-Villaverde et al. [
1], I introduce the volatility of risky asset returns into the model to depict financial volatilities. Consequently, I can investigate the cross-country transmission of economic cycles under both productivity and financial market volatility shocks. My findings highlight the significance of precautionary saving motives as a crucial mechanism in the cross-country transmission of uncertainty shocks. The impact of financial integration on business cycle synchronization crucially depends on the type of shock. In the presence of productivity volatility shocks, financial integration weakens the synchronization of economic cycles, whereas in the presence of financial volatility shocks, financial integration enhances the cross-country transmission of economic cycles. Moreover, in response to the ongoing debate about the pros and cons of financial integration, I conduct a welfare analysis. The quantitative results show that financial integration yields social welfare, regardless of the type of volatility shock.
The contagion mechanisms of the two kinds of volatility shocks work as follows: The first scenario characterizes how financial integration affects international dynamics in the presence of a productivity volatility shock. As the risk of domestic productivity fluctuations increases, precautionary savings by domestic residents increase, reducing bank deposit rates and, correspondingly, corporate lending rates. The decrease in lending rates is transmitted abroad through the interest rate channel, which enables firms in the foreign financially integrated sector to hire more labor at a lower cost and expand production. This, in turn, squeezes out loans from the domestic financially integrated sector. Thus, productivity volatility shocks lead to an unequal distribution of international bank loans between firms in the two countries, causing a reverse movement in firm investment and output. Consequently, when a productivity volatility shock occurs, countries with higher levels of financial integration demonstrate greater inequality in loan distribution, leading to more divergent business cycles. In contrast to productivity volatility shocks, financial volatility shocks impact sectors that hold risky assets in banks, especially for financially integrated sectors where both countries are equally exposed to volatility in international financial markets. Therefore, the larger the relative size of the financially integrated sector (i.e., the higher the degree of financial integration), the more synchronized the comovements in the business cycles of the two countries will be.
The existing theoretical literature has not yet conducted a detailed examination of the impact of financial integration on business cycle synchronization under uncertainty shocks. They overwhelmingly focus on the level of exogenous shocks (i.e., magnitude, persistence, or correlation), rather than second-order moments such as volatility. In studies that examine this issue from the perspective of uncertainty shocks, the majority of studies primarily concentrate on the volatility of productivity shocks [
3,
4,
5,
20,
21,
22]. Some other studies explore volatilities stemming from government spending shocks, consumption preference shocks, labor supply shocks, and monetary policy shocks [
23,
24]. Few studies focus on the uncertainty of financial shocks. However, note that, in reality, there is an external financing premium between loan rates and risk-free interest rates. Moreover, an increase in the volatility of interest rates in the financial market results in increased corporate financing risk, reflecting an elevated level of financial risk [
1,
19]. There is a scarcity of theoretical articles specifically addressing the volatility associated with financial shocks. In contrast, empirical studies focusing on this issue are abundant [
25,
26,
27,
28,
29,
30]. These studies analyze the volatility of financial shocks by examining stock market returns or the VIX index. They emphasize the crucial role of credit markets in the propagation of uncertainty shocks and highlight the significance of the level of financial development. The findings suggest that compared to developed economies, emerging economies with relatively lower levels of financial development and less robust capital markets typically experience stronger negative impacts from uncertainty shocks. This is primarily due to their limitations in mitigating risks through international financial markets.
The studies most relevant to this paper are Colacito et al. [
5], Silva-Yanez [
22], and Gete and Melkadze [
31]. Gete and Melkadze [
31] find that recursive preferences significantly improve the explanatory power of the theoretical model for the pass-through of output volatility and risk sharing across countries. Silva-Yanez [
22] investigates the effects of uncertainty shocks on foreign asset accumulation, risk sharing, and social welfare in emerging economies. The model shows that the presence of volatility shocks strengthens the precautionary saving motive and encourages a more significant accumulation of foreign assets in the small open economy. With increased financial integration, representative households can diversify income risk, thereby weakening the incentive for precautionary saving and reducing the willingness to accumulate foreign assets. However, Silva (2020) only examines TFP volatility shocks and overlooks the key role of financial volatilities. Gete and Melkadze [
31] document the cross-country patterns of uncertainty and credit variables with an international focus. By simultaneously examining the effects of uncertainty shocks on key economic variables, such as the current account, investment, output, and credit flows, he argues that the traditional IRBC model can explain the impact of uncertainty shocks on current account surplus, but it fails to account for credit contraction and increased risk premiums. To address this issue, Gete and Melkadze [
31] extends a two-country incomplete markets IRBC model by incorporating a credit supply channel that considers default and lenders’ exposure to aggregate risk. According to Gete and Melkadze [
31], uncertainty shocks increase the household sector’s incentive for precautionary saving, leading to a higher current account surplus. However, these shocks also increase firms’ default risk, which tightens bank credit and raises lending rates. Consequently, firms face difficulties in corporate financing, resulting in a simultaneous decline in their investment activities. Gete and Melkadze [
31] compares volatility shocks to the international rate and TFP in a small open economy model and suggests that these two types of shocks are observationally equivalent. In contrast to his research, I investigate a two-country model and discover that financial integration entails distinct transmission channels for the cross-country transmission of TFP volatility shocks and financial volatility shocks.
This paper is also related to the literature on the ongoing debate about the benefits of financial integration. The scholarly perception of the relationship between financial integration and social welfare has gradually evolved over time. Early studies expressed a positive outlook on financial globalization, emphasizing its potential to enhance consumption smoothing [
32,
33,
34,
35,
36,
37,
38,
39]. These studies highlighted the crucial role of capital markets in facilitating risk sharing. International credit markets provided increased liquidity. Additionally, cross-border asset holdings and diversified portfolios effectively diversified country-specific and nonsystematic risks. Consequently, financial integration was believed to effectively mitigate country-specific risk shocks, thereby promoting overall social welfare. In other studies, however, scholars have found that the impact of financial liberalization on international risk sharing is not significant [
40], especially for developing countries with low levels of financial integration [
41,
42,
43,
44,
45,
46,
47]. Bai and Zhang [
40] argue that in the presence of financial frictions and the risk of sovereign debt default, the removal of capital controls and deregulation of financial markets cannot deliver significant improvement in international risk sharing. Kim et al. [
41] discover that the degree of risk sharing among East Asian countries is significantly lower than in developed economies, with nearly 80% of shocks not being effectively shared. Capital markets play an insignificant role, while credit markets are effective but limited. Their research also explores the impact of regional and global risk sharing, leading to the conclusion that East Asian countries exhibit considerably less financial market integration than European financial markets. As a result, consumer risk sharing is more likely to be achieved through global financial markets. Other similar studies, such as Calvi et al. [
45], Yu et al. [
46] and Park and Lee [
47], mostly support the notion that the financial integration process in East Asian countries is relatively sluggish and lags behind the integration process in the real economy.
With the outbreak of the global financial crisis, many scholars began to reflect on the disadvantages of financial integration. The costs of financial integration can be summarized as follows: First, capital flows have aggregation effects and procyclicality. Historical experience shows that cross-border capital inflows are concentrated in only a few middle-income countries in Latin America and Asia, and small countries with low levels of economic development still face financing difficulties even if they open their capital accounts [
48,
49,
50]. Furthermore, capital flows are strongly procyclical. The influx of capital during economic booms causes capital overheating; the withdrawal of capital during economic downturns not only exacerbates the risk of runs [
51] but also causes liquidity crises for those firms that are overly dependent on capital. Second, capital mismatch can bring distortion. Overheated capital will lead to stock and housing bubbles, which will crowd out investment in the real economy and lead to numerous high-leverage and rent-seeking behaviors, hampering long-term economic growth [
52]. Moreover, financial integration serves as a significant channel that triggers economic volatility, as highlighted by Stiglitz [
53], Agénor [
52], Pancaro [
54], and Cavoli et al. [
55]. Pancaro [
54] argues that rather than aiding in smoothing consumption, capital liberalization has actually led to a rise in consumption volatility in emerging economies. This is particularly problematic for low-income countries, as excessive credit expansion can escalate credit risk and amplify output volatility.
This paper contributes to the growing literature on the study of financial integration in international dynamics. In comparison to other theoretical works, this paper possesses two advantages. On the one hand, by examining the issue through the lens of volatility shocks, the paper provides valuable insights. I investigate both productivity and financial market volatility shocks, uncovering distinct transmission mechanisms that differ from the findings of Gete and Melkadze [
31]. I argue that disregarding volatility shocks would underestimate the impact of financial integration on the comovement of business cycles and result in less accurate alignment of business cycle statistics with real data. On the other hand, the quantitative findings also contribute to the discussion on the benefits of financial integration. I find that financial integration plays a critical role in effectively mitigating the adverse impact of volatility shocks on social welfare. This is primarily because financial integration enables individuals and firms to save and borrow from international financial markets. As a result, precautionary saving motives are reduced, and consumption fluctuations caused by volatility shocks are dampened, leading to an enhancement in social welfare.
The paper is organized as follows:
Section 2 lays out the theoretical model.
Section 3 analyzes the quantitative results and compares the transmission mechanism under a TFP volatility shock and a financial volatility shock.
Section 4 performs a sensitivity analysis. Finally,
Section 5 concludes the paper.
2. Model
I construct a two-country, two-sector dynamic stochastic general equilibrium model with time-varying volatilities in an open economy. Each sector comprises households, firms, and commercial banks. Sector I is a financially closed sector, where commercial banks can only engage in borrowing and lending activities among firms and households within the same sector. On the other hand, sector II is a financially integrated sector, where financial transactions occur through global banks. The size of sector I is denoted as (), while sector II is represented by n. The exogenous parameter n reflects the degree of financial integration, with higher values indicating greater integration. The two countries in the model are perfectly symmetric, and their economic behaviors mirror each other. I provide a detailed description of the model setup, taking the home country as an illustrative example, and variables related to foreign counterparts are denoted with an asterisk.
2.1. Households
I introduce the Epstein-Zin recursive utility function, which offers a more accurate representation of the characteristics observed in the real economy. In contrast to the CRRA utility function, the Epstein-Zin recursive utility function enables the separation of the coefficient of relative risk aversion (RRA) and the intertemporal elasticity of substitution (IES) in the preference structure, that is, these two parameters are no longer inversely related. Recursive utility allows consumers to exhibit different attitudes toward current and intertemporal consumption risks, providing a more flexible characterization of consumers’ subjective attributes. Assuming homogeneity among households and a continuous distribution in the interval [0, 1], the objective of representative household is to maximize the expected lifetime utility function, which is expressed as follows:
where
,
,
is the intertemporal discount factor,
is the inverse of the labor supply elasticity,
is the labor level adjustment parameter,
is the risk aversion coefficient of households,
represents the IES, and the recursive utility function simplifies to the CRRA utility function when
.
The household’s budget constraint is given by
where
represents household consumption in sector
i in period
t,
is labor input,
is household savings in commercial banks from period
to
t,
is the deposit rate,
is the unit labor wage, and
is the corporate dividend. The household maximizes the lifetime utility equation (
2) under the budget constraint equation (
1) to obtain the corresponding first-order conditions:
Since sector II is fully financially integrated, households in both countries can allocate their savings to international commercial banks. Therefore, for sector II, the interest rates on savings in the home and foreign household sectors are equal, i.e., .
2.2. Firms
The representative firm is risk neutral, continuously distributed in the interval [0,1], and invests labor and capital in production activities in each period with a production function in Cobb-Douglas form:
Here,
and
represent capital inputs and labor inputs, respectively, and the coefficient
denotes the share of capital in output. Assume that productivity
follows a time-varying AR(1) process, and I introduce
and
to capture the volatility of productivity, which also follow an AR(1) process. Furthermore,
and
represent the productivity volatility shocks from the two countries, respectively, and they are assumed to follow an i.i.d. distribution. Finally,
and
represent the correlation coefficient matrix.
The manufacturer needs to borrow working capital from the bank to pay a portion of the workers’ wages prior to receiving sales revenue [
56,
57]. The firm’s optimization problem involves choosing various types of factor inputs and making investment decision to maximize its expected profits, taking into account investment adjustment costs:
where
is the stochastic discount factor, given by
.
represents the net profit of the firm after subtracting all operating expenses, including workers’ wages, firm investments, and interest on borrowed working capital. The profit of the representative firm can be expressed as:
Here, the product price is normalized to 1,
represents the firm’s investment,
denotes the proportion of total wages that the firm needs to borrow as working capital, and
denotes the interest rate on the firm’s financing loan. Similarly, in the case of sector II, where both domestic and foreign producers can borrow from global banks and achieve full financial integration, the borrowing interest rate faced by domestic and foreign manufacturers will be exactly the same. That is,
.
The dynamic capital accumulation equation is given by:
where
is the capital depreciation rate and
is the investment adjustment cost function and satisfies
,
, and
[
8,
58]. The settings of
and
make the steady state in the presence of investment adjustment costs consistent with the steady state in the absence of adjustment costs, satisfying
and
. Here,
is the capital depreciation rate, and
is the investment adjustment cost function, which satisfies
,
, and
[
8,
58]. The values of
and
are chosen such that the steady state with investment adjustment costs aligns with the steady state without adjustment costs, satisfying
and
.
The first-order condition obtained by solving the above optimal solution satisfies:
2.3. Commercial Banks
Commercial banks serve as a crucial intermediary between households and firms, performing the basic function of credit intermediation. Household savings in the non-financially integrated sectors in both countries are
and
, while the financially integrated sectors can save in international banks, and total household savings in sector two in both countries are
. There are two main uses of savings deposits in commercial banks; one is to provide risk-free corporate loans that are used as working capital for manufacturers, and the other is used to invest in risky assets.
and
denote the return on risky assets in each country, and the mean asset return is the same in both countries in equilibrium. Assume that the expected return on risky assets is high enough that each commercial bank invests the maximum share allowed by its bank regulation.
is used to denote this share and satisfies
. In sector I, commercial banks’ lending and investment activities are limited to that sector in that country, while in sector II, international banks can lend to manufacturers in both countries and allocate diversified international investments. Finally, referring to the model setting of Kalemli-Ozcan et al. [
14], commercial banks need to incur certain operating costs
to organize and manage various business activities. Under the assumption of competitive banks, the profit of commercial banks is zero in equilibrium:
Assuming that the returns on risky assets in both countries follow a bivariate AR(1) process, this paper incorporates the depiction of financial shock volatility into the model based on the approach proposed by Fernández-Villaverde and Rubio-Ramírez [
19] and Fernández-Villaverde et al. [
1].
where
represents the average return on risky assets,
and
denote the exogenous financial shocks in both countries, and
represents the fluctuations in the return on risky assets following an AR(1) process. The variables
and
represent the financial market volatility shocks in the two countries. All the variables,
,
,
, and
, are assumed to follow i.i.d distributions. The correlation coefficient matrices
and
are of size
.
2.4. Equilibrium
The equilibrium state of the entire economic system is defined as follows: given exogenous shocks and initial conditions, the price series , and the allocation sequence are determined in a way that satisfies the following conditions. The household sector maximizes expected lifetime utility, the producer maximizes expected profit, the budget constraint of each economic agent is satisfied, competitive commercial bank profits are zero, and each market clears.
The labor market clearing conditions are:
The total profits of firms are distributed among households in proportion to their individual dividends. In other words, the profit distribution is cleared according to the following mechanism:
The capital market is cleared under the condition that the working capital of each sector is equal to the loans provided in that sector. Specifically, in sector I, the bank loans are limited to advances for workers’ wages in each country’s sector I firms. In sector II, the working capital corresponds to the total global bank loans provided to sector II in both countries. This ensures that the capital market is in equilibrium and all capital requirements are met.
2.5. Calibration and Solution Method
I choose the parameter values based on relevant studies by Kollmann [
4] and Colacito et al. [
5], and set the risk aversion coefficient of consumers, denoted as
, to 10, and the IES, denoted as
, to 1.5. The parameters of the level shocks refer to the method of Kalemli-Ozcan et al. [
14]. To ensure comparability, I use
to match the quarterly GDP growth rate in the US of 1.32% in two cases.
is calibrated to
for productivity shock only and
when both productivity and financial shocks hit.
Regarding the parameters related to volatility shocks, the productivity volatility shock parameters are taken from Mumtaz and Theodoridis [
24]. The autocorrelation coefficient of productivity volatility, denoted
, is set to 0.99, and the variance of productivity volatility, denoted
, is calibrated to 0.065. The correlation of productivity volatility between the two countries is assumed to be 0, implying that productivity shocks are uncorrelated across countries [
3,
24,
59]. For the parameters related to financial volatility shocks, references are made to Mencia and Sentana [
60] and Skintzi and Refenes [
61]. The autocorrelation coefficient of financial volatility, denoted
, is set to 0.98, and the standard deviation of the variance, represented as
, is calibrated to 0.064. The autocorrelation coefficient
is set to 0.98. According to the VIX index
1 calculated by Ederington and Guan [
62], the standard deviation of the variance
is calibrated to 0.064. The correlation of financial volatility between countries is also assumed to be 0.
Following Mendoza [
63] and Perri and Quadrini [
15],
, the fraction of the wage bill that is paid in advance, is set to 0.26, matching the ratio of working capital to GDP in the data. The size of sector II,
n, is calibrated to match an average value of 0.15 for the level of financial integration in the U.S. during the sample period.
is calculated by BIS data, using the fraction
. The share and average return of risky assets is set to 0.4 and 0.06, according to the statistics in the U.S. [
14,
64]. Other parameter values are selected using the same settings as those in the international macro literature. For example, the discount factor
, the capital share
, the capital depreciation rate
, and the labor supply adjustment
are set such that the average yearly return to capital equals 4%, labor’s share of GDP equals 64%, the annual depreciation rate is 10 %, and the labor supply is approximately 1/3 in steady state. The parameter calibration values are summarized in
Table 1.
Since an exact solution for the DSGE model is not available, the Taylor approximation method, also known as the perturbation method, is commonly employed to obtain an approximate solution. This method linearizes the model by performing a Taylor expansion around the steady-state value. The first-order approximation solution, based on the principle of certainty equivalence in the first-order moment expansion, assumes a risk premium of 0. The second-order approximation, although influencing the level of the risk premium, fails to capture the volatility of uncertainty shocks, which are shocks characterized by exogenous shock variance. Given that the model does not feature an occasionally binding constraint, the higher-order approximation is expected to provide a more accurate solution closer to the global solution. Moreover, the higher-order approximation facilitates handling models with a greater number of state variables, as is the case in this paper. Therefore, I employ a high-order approximation to solve the model. This approach not only compensates for the zero risk premium in the first-order approximation and the constant risk premium in the second-order approximation, which cannot account for time-varying uncertainty shocks, but it also allows me to quantify the welfare changes resulting from financial integration under various types of external shocks [
3,
59,
66].