t = 1:1:(500+2);
t = t'; % Create the time vector for x-axis.
g = t;
g(2:502) = 1.1; % Specify the path of government expenditure.
T = 500; % Spedcify the x-axis length.

subplot(2,2,1)
plot(t(1:500), g(1:500), 'r-')
grid on; grid minor;
axis([0 T 0.9 1.2])
g_title = title('Government intervention vs. time');
g_xlabel = xlabel('Time Period');
g_ylabel = ylabel('Shock (from government), g');
g_title.FontName = 'Segoe UI Semibold';
g_title.FontSize = 12;
g_title.FontWeight = 'bold';
g_xlabel.FontName = 'Segoe UI Semibold';
g_xlabel.FontSize = 11;
g_xlabel.FontWeight = 'bold';
g_ylabel.FontName = 'Segoe UI Semibold';
g_ylabel.FontSize = 11;
g_ylabel.FontWeight = 'bold';

subplot(2,2,2)
plot(t, k, 'r')
grid on; grid minor;
axis([0 T 37.5 39])
k_title = title('Capital vs. time');
k_xlabel = xlabel('Time Period');
k_ylabel = ylabel('Capital, k');
k_title.FontName = 'Segoe UI Semibold';
k_title.FontSize = 12;
k_title.FontWeight = 'bold';
k_xlabel.FontName = 'Segoe UI Semibold';
k_xlabel.FontSize = 11;
k_xlabel.FontWeight = 'bold';
k_ylabel.FontName = 'Segoe UI Semibold';
k_ylabel.FontSize = 11;
k_ylabel.FontWeight = 'bold';

subplot(2,2,3)
plot(t(1:500), c(1:500), 'r-')
axis([0 T 1.62 1.8])
grid on; grid minor;
c_title = title('Consumption vs. time');
c_xlabel = xlabel('Time Period');
c_ylabel = ylabel('Consumption, c');
c_title.FontName = 'Segoe UI Semibold';
c_title.FontSize = 12;
c_title.FontWeight = 'bold';
c_xlabel.FontName = 'Segoe UI Semibold';
c_xlabel.FontSize = 11;
c_xlabel.FontWeight = 'bold';
c_ylabel.FontName = 'Segoe UI Semibold';
c_ylabel.FontSize = 11;
c_ylabel.FontWeight = 'bold';

subplot(2,2,4)
plot(t, y, 'r')
axis([0 T 3.7 3.74])
y_title = title('Production vs. time');
y_xlabel = xlabel('Time Period');
y_ylabel = ylabel('Production, y');
grid on; grid minor;
y_title.FontName = 'Segoe UI Semibold';
y_title.FontSize = 12;
y_title.FontWeight = 'bold';
y_xlabel.FontName = 'Segoe UI Semibold';
y_xlabel.FontSize = 11;
y_xlabel.FontWeight = 'bold';
y_ylabel.FontName = 'Segoe UI Semibold';
y_ylabel.FontSize = 11;
y_ylabel.FontWeight = 'bold';