July 2014

van der Ploeg, De Zeeuw, 31 July 2014, 18990 reads

Many ecological systems feature ‘tipping points’ at which small changes can have sudden, dramatic, and irreversible effects, and scientists worry that greenhouse gas emissions could trigger climate catastrophes. This column argues that this renders the marginal cost-benefit analysis usually employed in integrated assessment models inadequate. When potential tipping points are taken into account, the social cost of carbon more than triples – largely because carbon emissions increase the risk of catastrophe.

Eichengreen, Panizza, 30 July 2014, 51872 reads

For the debts of European countries to be sustainable, their governments will have to run large primary budget surpluses. But there are both political and economic reasons to question whether this is possible. The evidence presented in this column is not optimistic about Europe’s crisis countries. Whereas large primary surpluses for extended periods of time did occur in the past, they were always associated with exceptional circumstances.

Kawase, 29 July 2014, 20317 reads

The regulation of state-owned enterprises in international trade dealings has been cited as a major stumbling block to progress on the Trans-Pacific Partnership negotiations. This column explains the issues of contention, and argues that state-owned enterprises require an explicit and deliberate regulatory treatment. Given their unique properties, a coherent approach to state-owned enterprise regulation would promote progress in negotiations better than the piecemeal of overlapping rules currently considered.

Bertocchi, Gambardella, Jappelli, Nappi, Peracchi, 28 July 2014, 16269 reads

Assessing the quality of academic research is important – particularly in countries where universities receive most of their funding from the government. This column presents evidence from an Italian research assessment exercise. Bibliometric analysis – based on the journal in which a paper was published and its number of citations – produced very similar evaluations of research quality to informed peer review. Since bibliometric analysis is less costly, it can be used to monitor research on a more continuous basis and to predict the outcome of future peer-reviewed assessments.

Chodorow-Reich, 27 July 2014, 19826 reads

The monetary policies implemented by the Federal Reserve since late 2008 have raised concerns about the risk taking of financial institutions. This column discusses the effect of some of these policies on life insurance companies and market mutual funds. While the effect on life insurance companies has been stabilising, money market funds did not actively reach for yield.

Goldberg, Krogstrup, Lipsky, Rey, 26 July 2014, 20111 reads

The dollar’s dominant role in international trade and finance has proved remarkably resilient. This column argues that financial stability – and the policy and institutional frameworks that underpin it – are important new determinants of currencies’ international roles. While old drivers still matter, progress achieved on financial-stability reforms in major currency areas will greatly influence the future roles of their currencies.

Edmans, 25 July 2014, 22560 reads

Happy workers might well be more productive than unhappy ones, but high worker satisfaction could also be a sign that workers are overpaid or underworked. This column examines the link between worker satisfaction and future stock returns in 14 countries. In most but not all countries, employee satisfaction is associated with higher future stock returns. Abnormal returns to companies with high worker satisfaction are significantly increasing in the flexibility of their countries’ labour markets.

Beck, Degryse, De Haas, van Horen, 25 July 2014, 17606 reads

The small and medium-size enterprises (SMEs) were among the most severely affected in the Global Crisis. This column discusses new evidence on how different lending techniques affect lending in bad and good times. Data from 21 countries in central and eastern Europe show that ‘relationship lending’ alleviates credit constraints during a cyclical downturn but not during a boom period. The positive impact of relationship lending in an economic downturn is strongest for smaller and more opaque firms and in regions where the downturn is more severe.

Kupers, 25 July 2014, 15773 reads

Complexity science is changing the way we think about social systems and social theory. Unfortunately, economists’ policy models have not kept up and are stuck in either a market fundamentalist or government control narrative. This Vox Talk argues for a new, more flexible policy narrative, which envisions society as a complex evolving system that is uncontrollable but can be influenced.

Komlos, 24 July 2014, 14662 reads

Many quantities fail to respond smoothly to price changes. This column stresses that the ‘endowment effect’ – a well-known behavioural economics concept – implies kinks in indifference curves at the current consumption bundle price. Such kinks may account for the stickiness of prices, wages, and interest rates.

Behrens, Robert-Nicoud, 24 July 2014, 24985 reads

Large cities are more unequal than the nations that host them. This column argues that this is because large cities disproportionately reward talented superstars and disproportionately ‘fail’ the least talented. Cities should thus be the primary focus of policies to reduce inequality and its adverse consequences for society.

Broner, Erce, Martin, Ventura, 23 July 2014, 19673 reads

Since 2010, Eurozone periphery countries have faced severe debt problems and falling credit to the private sector. This column interprets these events with a theory that has three main ingredients. First governments can favour domestic creditors. Second, public debt trades in secondary markets so debt holdings shift from foreign to domestic residents. Third, due to private financial frictions, this shift crowds out private investment and growth.

Massetti, Ricci, 23 July 2014, 17548 reads

Concentrated solar power generation in Northern African and Middle Eastern deserts could potentially supply up to 20% of European power demand. This column evaluates the technological, economic, and political feasibility of this idea. Although concentrated solar power is a proven technology that can work at scale, it is currently four or five times more expensive than fossil fuels. Concentrated solar power could play an important role in Europe’s energy mix after 2050, but only if geo-political challenges can be overcome.

Frankel, 22 July 2014, 26394 reads

The US court ruling forcing Argentina to pay its hold-out creditors has big implications. This column argues that some of them are particularly worrying. The court ruling undermines the possibility of negotiated re-structuring of unsustainable debt burdens in future crises. In the future, it will not be not enough for the debtor and 92% of creditors to reach an agreement, if holdouts and a New York judge can block it. This will make both debtors and creditors worse-off.

Bénassy-Quéré, Trannoy, Wolff, 22 July 2014, 15130 reads

Tax harmonisation has been controversial since the establishment of the European Economic Community, and corporation tax proposals are currently on the table in the EU. Although tax competition can be beneficial, tax harmonisation could curb tax competition that leads to the under-provision of public goods or to burden-shifting from mobile to immobile tax bases. As yet, no agreement has been reached on any ambitious harmonisation plan for mobile tax bases. This column explores the possibility of implementing partial tax harmonisation for corporate taxation and the taxation of the banking sector.

Zhang, 21 July 2014, 13224 reads

The Chinese government has been actively promoting innovation via policies such as R&D subsidies, tax relief, and location policies. Since 1995, central and local governments have established more than 100 clusters in over 60 cities. This column presents new evidence on the effect of the concentration of firms on product innovation (new products) in the manufacturing industries.

Laeven, Ratnovski, 21 July 2014, 22018 reads

Bank distress during the recent crisis caused significant damage to the real economy. Appropriately, the policy response focused on stronger bank supervision and regulation. This column asks if there is a role for improvements in bank corporate governance. Based on the literature the authors suggest that better risk management, regulation of pay, and enhanced market discipline can help make banks safer. However, corporate governance cannot substitute for strong supervision: it can at best provide a helping hand.

Saha, 20 July 2014, 16306 reads

An early draft of the Transatlantic Trade and Investment Partnership (TTIP) sparked an intensive public debate over possible advantages and disadvantages. This column reviews some arguments in favour of the Partnership and against it. While there is some debate over how large the economic benefit could be in the face of already relatively low trade barriers, critics claim that the deal will lower standards of consumer protection, provision of public services, and environmental protection in the EU.

Morikawa, 20 July 2014, 10911 reads

Innovation is a key driver of productivity growth, but innovation in the service sector has received relatively little attention. This column shows that the total factor productivity gap between Japanese firms with and without innovations is larger in services than in manufacturing. Whereas the percentage of firms holding patents is much higher in manufacturing than in services, trade secrets are just as important in both sectors. These results suggest that the protection of trade secrets makes an important contribution to productivity growth.

Yang, 19 July 2014, 35140 reads

In China, both unemployment and a labour shortage have emerged as problems in recent years. This column explains their co-existence by a decrease in the matching efficiency in the labour market. One way to improve the matching efficiency, though difficult to implement in the short-run, is through the creation of more employment agencies. Companies can benefit if they invest more in recruiting activities.

Gennaioli, Martin, Rossi, 19 July 2014, 17089 reads

There is growing concern – but little systematic evidence – about the relationship between sovereign default and banking crises. This column documents the link between public default, bank bondholdings, and bank loans. Banks hold many public bonds in normal times (on average 9% of their assets), particularly in less financially developed countries. During sovereign defaults, banks increase their exposure to public bonds – especially large banks, and when expected bond returns are high. At the bank level, bondholdings correlate negatively with subsequent lending during sovereign defaults.

McKeown, Paterson, 18 July 2014, 12326 reads

The Bank of England has introduced a series of changes aimed at enhancing the transparency of its flagship communication vehicle for monetary policy – the Inflation Report. This column by two BoE economists sets the rationale for these changes in the context of the economic literature.

Kashyap , Tsomocos, Vardoulakis, 18 July 2014, 16362 reads

Do the extant workhorse models used in policy analysis support macroprudential and macrofinancial policies? This column argues that this is not the case and describes a new macroprudential model that stresses the special role played by banks. The model also accounts for two, often neglected, key principles of the financial systems. Some of the findings of the model could carry over to other, more general settings that satisfy these two principles.

Layard, Clark, 17 July 2014, 25982 reads

Mental illness is the main sickness of the working age population with economic costs around 8% of GDP. This column, based on the authors’ recent book, discusses the effectiveness of a large programme of psychological therapy, launched in England in 2008. The savings due to welfare benefits, extra taxes, and physical healthcare outweigh the costs of the programme. In this case, psychological therapy costs nothing.

Clements, Feher, Gupta, 17 July 2014, 11801 reads

The discussion on pension reform typically centres on fiscal sustainability. This column argues that equity concerns are of primary importance, both in selling proposed reforms to the public, and as a first-order policy goal of the pension system. Focusing on the average pensioner is insufficient to evaluate policy.

Algan, Cahuc, Sangnier, 17 July 2014, 24379 reads

It is commonly argued that the persistence of large welfare states in Scandinavian countries is due to the trustworthiness of their citizens. This column shows that the relationship between trust and the size of the welfare state is twin peaked. Untrustworthy individuals support generous welfare states because they expect to benefit without bearing the costs, whereas civic-minded individuals only support generous welfare states when surrounded by people they trust.

Deaton, Aten, 16 July 2014, 16371 reads

When the international comparison project published its latest estimates of purchasing power parity exchange rates in April there was some consternation. Poor countries became richer overnight, world GDP increased, and global income inequality was revised downwards. Alas, no one stopped being poor. This column digs into the numbers to see if we’ve been consistently underestimating the relative size of poorer economies and overestimating global poverty and inequality.

Hoekman, Mavroidis, 16 July 2014, 11727 reads

The proliferation of trade ‘clubs’ indicates that governments are keen on engaging in trade liberalisation. This column argues that the creation of new trade clubs under the umbrella of the WTO is inevitable. Such issue-specific (plurilateral) agreements keep the cord with the WTO tight, while allowing countries to cooperate on issues outside of WTO’s grounds.

Restrepo, Rieger, 16 July 2014, 13719 reads

Artificial trans fat is omnipresent in the global food chain, but the medical consensus is that it increases the risk of developing cardiovascular diseases such as heart disease and stroke. Between 2007 and 2011, New York City and six other county health departments implemented bans on trans fat in restaurants. This column presents the first evaluation of the effect of these bans on cardiovascular disease mortality rates.

Benkovskis, Woerz, 15 July 2014, 13190 reads

Import price statistics may not be a reliable indicator of welfare gains. They must adequately reflect the fact that consumers value variety, and that consumer tastes and product quality change over time. This column evaluates existing findings, and introduces new results for the four largest EU economies – including evidence of higher consumer welfare gains than suggested by official import prices for the period from 1995 to 2012.

Chiţu, Eichengreen, Mehl, Richardson, 15 July 2014, 15626 reads

The European debt crisis has triggered debates over the TARGET2 imbalances. This column discusses gold flows across Federal Reserve districts and points to the similarity of such operations to liquidity flows from Eurozone’s ‘core’ to its ‘periphery’. Though the institutional setting in Europe differs, important lessons can be drawn from the US example. Cooperation between regional Reserve Banks was essential for the cohesion of the US monetary union. Such cooperative spirit will be important for the smooth operation of the Eurozone.

Ariel Aaronson, 14 July 2014, 17119 reads

The internet promotes educational, technological, and scientific progress, but governments sometimes choose to control the flow of information for national security reasons, or to protect privacy or intellectual property. This column highlights the use of trade rules to regulate the flow of information, and describes how the EU, the US, and their negotiating partners have been unable to find common ground on these issues. Trade agreements have yet to set information free, and may in fact be making it less free.

Bas, Strauss-Kahn, 14 July 2014, 14420 reads

The rise of trade in intermediate inputs is well documented, but its role in shaping domestic economies is not yet completely understood. This column presents evidence from French firms on the effects of importing intermediate inputs. Firms importing more varieties of intermediate inputs increased their productivity and exported more varieties. Foreign inputs from the most advanced economies have the strongest effect on firm productivity, but imported inputs from all countries help raise the number of export varieties.

Wood, 13 July 2014, 16113 reads

The Global Crisis triggered a series of medium-term policy changes. This column reviews the effectiveness of some of these monetary, fiscal policies, and internal devaluation policies. Policymakers anchored their strategic thinking in paradigms that became inapplicable to the new problems. An alternative set of macroeconomic policies is suggested.

Voigtländer, Squicciarini, 13 July 2014, 20514 reads

Although studies of contemporary economies find robust associations between human capital and growth, past research has found no link between worker skills and the onset of industrialisation. This column resolves the puzzle by focusing on the upper tail of the skill distribution, which is strongly associated with industrial development in 18th-century France.

Ellen, Remes, 12 July 2014, 12884 reads

Brazil has grown rapidly and reduced poverty over the past decade, but it has grown more slowly than other emerging economies and its income per capita remains relatively low by global standards. This column points out that sectors of the Brazilian economy that have been opened up to international competition have outperformed those that remain heavily protected. Deeper integration into global markets and value chains could provide competitive pressures that would improve Brazil’s productivity and living standards.

Fajgelbaum, Redding, 12 July 2014, 11691 reads

External integration is often viewed as an important driver of economic development, but most existing studies use aggregate data. This column present evidence from a natural experiment provided by Argentina’s integration into the world markets in the late 19th century. The findings suggest that proximity to trade centres is associated with employment density, high lands rates relative to wages, and structural transformation away from agriculture.

Ghani, Kerr, Tewari, 11 July 2014, 11867 reads

Some cities grow through specialisation others through diversity. This column measures specialisation and diversity for the manufacturing and services sectors in India. It finds that Indian districts with a broader set of industries exhibit greater employment growth. This is particularly true for low population densities, rural areas and unorganised sector, reflecting knowledge flow and the inclusive nature of employment growth due to diversity.

Teulings, 11 July 2014, 21434 reads

The financial crisis and the Great Recession have led to calls for more economic history in economic education. This column argues for a much broader use of history in economics courses, as a device for teaching both the logic and the empirical relevance of economics. A proposed curriculum would include the rise of agriculture, urbanisation, war, the rule of law, and demography.

Atkinson, Casarico, Voitchovsky, 10 July 2014, 20562 reads

The glass ceiling is typically examined in terms of the distribution of earnings. This column discusses the glass ceiling in the gender distribution of total incomes, including self-employment and capital income. Evidence from Canada and the UK shows we are still far from equality. Though the proportion of women in the top 1% has been rising, the progress is slower, almost non-existent, at the very top of the distribution.

Ishizuka, 10 July 2014, 18257 reads

Japan has one of the highest labour market gender gaps among the advanced economies. This column examines the current status of gender diversity in management in Japan, China, and South Korea. Despite some pronounced differences, economic gender gaps are large in all of the three countries. But overall, gender diversity in management in Japan is slowly beginning to emerge.

Maçães, 09 July 2014, 18435 reads

The debate on the future of the European Union is in full swing. In this column, Bruno Macaes – the Portuguese Minister for Europe – stresses the importance of policy coordination in achieving better integration. One way to do so is via a fiscal union, but this creates unity at the expense of diversity. A second way involves formal contracts and partnerships. But to make this approach less rigid, the political dialogue does not need to be formalised in actual contracts.

Martínez, Musacchio, Viarengo, 09 July 2014, 9524 reads

Institutions are known to play a powerful and enduring role in countries’ divergent levels of economic development. This column presents evidence that institutions matter for within-country inequality, too. In Brazil, changes in export prices and export tax revenues led to an increase in education spending in states that experienced commodity booms, which increased the number of schools and improved educational outcomes such as literacy rates. However, the effect was limited in states where slavery was predominant in colonial times.

James, 09 July 2014, 25935 reads

The 1907 panic affected the world, demonstrating the fragility of the international financial system. This column discusses the steps the US and Germany took in fortifying their financial systems following 1907. There is a link between the financial crisis and the escalation of diplomatic relations that led to war in 1914. And this link has implications for today as the world is recovering from the 2008 crisis.

Bonfiglioli, Gancia, 08 July 2014, 11706 reads

Differences in labour market and firm statistics between the US and Europe are easy to dismiss as cultural. This column applies an equilibrium model of worker screening and effort to cross-country data, showing that a large chunk of observed differences can be explained by the strategic interaction between firm and worker strategies. Evidence suggests that the US is in a high-screening, high-effort equilibrium, while southern Europe is in the complementary equilibrium. Perhaps culture is more economic than we might assume.

Armstrong, Caselli, Chadha, den Haan, 08 July 2014, 16056 reads

How should UK policy-makers respond to potential dangers to the economy from the housing market? As this column reports, a majority of respondents to the fourth monthly survey of the Centre for Macroeconomics (CFM) think that house price dynamics do pose a risk to the UK’s recovery; and that macroprudential tools rather than traditional interest rate policy should be deployed to deal with this risk.

Görg, Godart, Hanley, Krieger-Boden, 08 July 2014, 28110 reads

Many firms are replacing traditional working hours with more flexible arrangements, reflecting new thinking on employee motivation. This column presents evidence from Germany that trust-based working time is associated with increased innovation. However, trust-based working hours also contribute to the blurring of workers’ professional and private lives, and may lead to excessive overtime. Careful design of trust-based working arrangements is required to reap the innovations gains while avoiding the health pitfalls.

De Grauwe, 07 July 2014, 38905 reads

There has been a stark contrast between the experiences of Spain and the UK since the Global Crisis. This column argues that although the ECB’s Outright Monetary Transactions policy has been instrumental in reducing Spanish government bond yields, it has not made the Spanish fiscal position sustainable. Although the UK has implemented less austerity than Spain since the start of the crisis, a large currency depreciation has helped to reduce its debt-to-GDP ratio

Cosar, Guner, Tybout, 07 July 2014, 15306 reads

Trade liberalisations are often accompanied by labour market reforms, making it difficult to isolate their effects. This column discusses the effects of trade liberalisation, globalisation, and labour-market reforms on the Colombian labour market. Reduced trade frictions increased cross-firm wage inequality and shifted the firm-size distribution rightward, with offsetting effects on overall wage inequality. Average income increased, but the gains were concentrated among employees of large, productive firms with access to export markets. Greater trade openness also increased job turnover.

Dachs, Zahradnik, 06 July 2014, 11950 reads

The Global Crisis brought a halt to three decades of R&D internationalisation, in which foreign firms’ share of total R&D expenditure had increased in almost all countries where data is available. However, this column argues that the crisis did not lead to a new global distribution of overseas R&D expenditure, despite the erosion of the EU’s share. The persistence of R&D expenditure is attributed to the costs of relocating R&D and to the autonomy of foreign subsidiaries.

Van Schaik, 06 July 2014, 35993 reads

Piketty’s book “Capital in the 21st century” has gained popularity with its finding of a growing gap between wage earners and capital owners. This column presents a test to the two main laws in Piketty’s book. The attractiveness of these two laws is in their simplicity, but so is their limitation. Piketty neglects investment replacement and depreciation.

Monnet, 05 July 2014, 14744 reads

The Global Crisis has raised the interest of banks in using quantitative controls, such as credit controls. This column discusses a relatively recent historical episode of credit controls in France. During this episode the role of interest rates was almost eliminated. Quantitative controls effectively decreased output and prices in the short-run. The difficulty for the Central Bank stemmed from the fact that it had to change its instruments constantly. This historical episode demonstrates that macroprudential tools can have substantial effects on monetary policy.

Martin, Ventura, 05 July 2014, 17453 reads

There is a widespread view among macroeconomists that fluctuations in collateral are an important driver of credit booms and busts. This column distinguishes between ‘fundamental’ collateral – backed by expectations of future profits – and ‘bubbly’ collateral – backed by expectations of future credit. Markets are generically unable to provide the optimal amount of bubbly collateral, which creates a natural role for stabilisation policies. A lender of last resort with the ability to tax and subsidise credit can design a ‘leaning against the wind’ policy that replicates the ‘optimal’ bubble allocation.

Svensson, 05 July 2014, 21997 reads

Sweden has pursued a tighter monetary policy than is necessary to achieve the inflation target in order to reduce risks associated with household indebtedness. The net benefit to ‘leaning against the wind’ has been hotly debated; this column argues strongly against it. By reducing inflation, the Riksbank has in fact increased household debt, and contractionary pressure has worsened the employment situation. The author estimates that the benefits to leaning are worth only 0.4% of the costs.

Sayek, Taskin, 05 July 2014, 13816 reads

The European Monetary Union is unprecedented, but the Eurozone Crisis is not. This column draws upon the experiences of previous banking crises, and compares the Eurozone Crisis countries. Like Japan before the 1992 crisis, Spain and Ireland had property bubbles fuelled by domestic credit. The Greek crisis is very distinct from crises in other Eurozone countries, so a one-size-fits-all policy would be inappropriate. The duration and severity of past crises suggest the road ahead will continue to be very rough.

Buti, Turrini, van den Noord, 04 July 2014, 15247 reads

Structural reforms are presumed to deteriorate a government’s chance for re-election. This column, which is an update from earlier work, provides evidence of just the opposite – the odds of re-election are larger for reformist than for non-reformist governments. This holds if the financial system is not overly regulated and an adequate social safety net is present.

Bond, Lang, 04 July 2014, 16798 reads

Self-reported measures of happiness are growing in popularity as alternatives to GDP. This column presents a novel statistical critique of the validity of comparing such measures across groups. Since monotonic transformations of individuals’ happiness levels can reverse average happiness rankings between countries, no meaningful comparison can be made without assumptions on the distribution of happiness.

Berger, Vavra, 03 July 2014, 12348 reads

Various stimulus programmes have been implemented in a response to the decline in consumption of durables since the Recession. This column argues that standard analysis of such programmes could be overstating their effectiveness. Aggregate durable spending is much less responsive to stimulus during recessions. Microeconomic frictions lead households to adjust their durable holdings less frequently.

Aizenman, 03 July 2014, 29022 reads

After a promising first decade, the Eurozone faced a severe crisis. This column looks at the Eurozone’s short history through the lens of an evolutionary approach to forming new institutions. German dominance has allowed the euro to achieve a number of design objectives, and this may continue if Germany does not shirk its responsibilities. Germany’s resilience and dominant size within the EU may explain its ‘muddling through’ approach to the Eurozone crisis. Greater mobility of labour and lower mobility of under-regulated capital may be the costly ‘second best’ adjustment until the arrival of more mature Eurozone institutions.

Hautcoeur, Riva, White, 02 July 2014, 12089 reads

The key challenge for lenders of last resort is to ameliorate financial crises without encouraging excessive risk-taking. This column discusses the lessons from the Banque de France’s successful handling of the crisis of 1889. Recognising its systemic importance, the Banque provided an emergency loan to the insolvent Comptoir d’Escompte. Banks that shared responsibility for the crisis were forced to guarantee the losses, which were ultimately recouped by large fines – notably on the Comptoir’s board of directors. This appears to have reduced moral hazard – there were no financial crises in France for 25 years.

Melitz, 02 July 2014, 18919 reads

As the Eurozone cautiously implements stabilising reforms, Germany is forced to go further with concessions than it would prefer. This column suggests that it would be beneficial for discontented members to consider the formation of a second monetary union. The second euro can be constructed better than the first, bringing the discontented members exchange-rate adjustments relative to Germany, and avoiding competitive devaluations.

Menon, 01 July 2014, 17080 reads

The Trans-Pacific Partnership (TPP) is taking a long time to conclude. This column argues that the TPP agenda, unlike the Doha round, is more ambitious and controversial. Many see it as skewed in favour of one country – the US. There are fears that even the US may lose interest in the Partnership without the fast-track authority given by the current Congress. The only useful way forward is for countries to take matters in their own hands.

Ball, 01 July 2014, 29525 reads

Whereas textbook macroeconomic theory suggests that output should return to potential after a recession, there is mounting evidence that deep recessions have highly persistent effects on output. This column reports estimates of the long-term damage caused by the Great Recession. In most countries in the sample, the loss of potential output – 8.4% on average – has been almost as large as the loss of actual output. In the countries hit hardest by the recession, the growth rate of potential output is much lower today than it was before 2008.