【正文】 2020 Pearson AddisonWesley. All rights reserved. 1644 Lessons for Moary Policy (cont’d) ? Moary policy can be highly effective in reviving a weak economy even if shortterm interest rates are already near zero ? Avoiding unanticipated fluctuations in the price level is an important objective of moary policy, thus providing a rationale for price stability as the primary longrun goal for moary policy 。 2020 Pearson AddisonWesley. All rights reserved. 1642 Credit View (cont’d) ? Cash flow channel Expansionary moary policy → i ↓→ cash flow ↑ → adverse selection ↓, moral hazard ↓→ lending ↑ → I ↑ → Y ↑ ? Unanticipated price level channel Expansionary moary policy → unanticipated P ↑ → real worth ↑ → → adverse selection ↓, moral hazard ↓→ lending ↑ → I ↑ → Y ↑ ? Household liquidity effects Expansionary moary policy → Ps ↑ → value of financial assets ↑ → likelihood of financial distress ↓→ consumer durable and housing expenditure↑ → Y ↑ Copyright 169。 2020 Pearson AddisonWesley. All rights reserved. 1640 Asset Price Effects (cont’d) ? Tobin’s q theory Expansionary moary policy ? Wealth effects Expansionary moary policy ???????? YIqP s????? w e a l t hP s???? Ync o n s u m p t i oCopyright 169。 2020 Pearson AddisonWesley. All rights reserved. 1638 FIGURE 3 The Link Between Moary Policy and GDP: Moary Transmission Mechanisms Copyright 169。 2020 Pearson AddisonWesley. All rights reserved. 1636 Statistical Evidence ? Autonomous expenditure variable (A) equal to investment spending plus government spending – For Keynesian model A should be highly correlated with aggregate spending but money supply should not – For Moarist money supply should be highly correlated with aggregate spending but A should not ? Neither model has turned out be more accurate than the other Copyright 169。 2020 Pearson AddisonWesley. All rights reserved. 1634 Timing Evidence of Early Moarists ? Money growth causes business cycle fluctuations but its effect on the business cycle operates with “l(fā)ong and variable lags” ? Post hoc, ergo propter hoc – Exogenous event – Reduced form nature leads to possibility of reverse causation – Timing evidence is hard to interpret Copyright 169。 2020 Pearson AddisonWesley. All rights reserved. 1632 Objections to Early Keynesian Evidence ? Friedman and Schwartz publish a moary history of the . showing that moary policy was actually contractionary during the Great Depression ? Many different interest rates ? During deflation, low nominal interest rates do not necessarily indicate expansionary policy ? Weak link between nominal interest rates and investment spending does not rule out a strong link between real interest rates and investment spending ? Interestrate effects are only one of many channels Copyright 169。 2020 Pearson AddisonWesley. All rights reserved. 1630 ReducedForm Advantages and Disadvantages ? Advantage – No restrictions imposed on the way moary policy affects the economy ? Disadvantage – Correlation does not necessarily imply causation ? Reverse causation ? Outside driving factor Copyright 169。 2020 Pearson Addiso