Replication and reanalysis, lack of incentive for

The problem is especially pronounced in the social sciences. I’d guesstimate perhaps 2% of the pages in the leading economics, policy, political science, and sociology journals feature replication and/or reanalysis. We ought to aim for something in the neighborhood of 33%.

Why the continued preference for new theory and analysis? My guess is simple path dependence. Until recently data were relatively scarce. Replication and reanalysis was no less valuable than today, but it was more difficult, time-consuming, and expensive. That’s changed profoundly. Yet the norm at most journals hasn’t. It should.

Where the journals go, tenure committees will follow.

Then again, perhaps the shift can happen without the journals.

What’s the signal that we may be headed for a “lost decade”?

“After a recession, this economy usually gets people back to work quickly. Not this time.” That’s Clive Crook in a recent FT column.

Actually, the lack of employment recovery since the official end of the great recession looks quite similar to what happened in the early 1990s and early 2000s (more data here, here, here).

If the degree of employment recovery is our signal, at this point we might indeed forecast a lost business cycle (“decade”), as in the 2000s, with the employment rate never even reaching its previous peak. But we might just as reasonably hope for a very healthy upturn, as in the 1990s.

We should be worried not just because employment growth so far has been sluggish, but also because:

1. This recession was much more severe than the previous two. We have a good bit more ground to make up.

2. Output may recover more slowly than in the past. Heavy household debt and the collapse of home values are likely to hamper consumption growth, and the Fed and Congress seem unwilling to further stimulate the economy.

3. The pattern of the 2000-07 business cycle may indicate a fundamental shift in employer practices, with greater reluctance to hire and eagerness to fire.

Update: More here from Josh Bivens and Isaac Shapiro at the Economic Policy Institute.

Relative poverty rates can mislead

Many researchers and policy makers favor a “relative” measure of poverty. That’s because our notion of what constitutes a minimally acceptable standard of living tends to be shaped by what’s typical in our own society. This approach dates back at least to Adam Smith. Its contemporary popularity owes much to Peter Townsend and Amartya Sen, and to the fact that the European Union’s official poverty measure is a relative one.

A relative poverty measure is essentially a measure of inequality within the bottom half of the income distribution. As long as this is made clear, such a measure can serve a purpose. But it’s fairly common for commentators to refer to a relative poverty rate as though it’s an indicator of absolute well-being. A journalist or opinion writer or researcher may say something like “We’ve failed to make things better for the poor; the poverty rate is the same now as a decade ago.” When hearing this, some (many?) of us will assume it reflects stagnant incomes for households at the bottom. But low-end incomes may actually have increased; that can happen without yielding any reduction in the relative poverty rate if incomes in the middle rise too.

Consider the experiences of six rich nations from the late 1970s to the mid-2000s. The following charts show trends in relative poverty and in absolute inflation-adjusted household income at the tenth percentile (a good proxy for “the poor”) in three of the six: the United States, Canada, and Germany. In each of these three countries the relative poverty rate increased slightly over the period. And in each of them absolute incomes of low-end households were flat or increased only minimally. Relative poverty rates and absolute incomes tell a consistent tale.

The story is quite different in Sweden, Norway, and Ireland. Here too relative poverty rates were flat or slightly rising. But in these three countries the absolute incomes of low-end households increased by a substantial amount. The reason the relative poverty rate in these countries didn’t fall is that household incomes at the median increased just as rapidly.

Relative poverty is of some interest, to be sure. But to avoid confusion, we might do well to sometimes refer to it as “lower-half inequality.”

Reducing relative poverty

Reducing poverty is widely viewed as a key objective of a good society. The U.K.’s Labour government set a formal poverty reduction target in the late 1990s, and the European Union recently did so as well. In the United States, public opinion surveys consistently find a solid majority saying government spends too little money on assistance to the poor.

The standard poverty measure in comparisons of rich nations is a “relative” one. The poverty line for each country is set at a percentage, usually 60% or 50%, of that country’s median household income.

Which countries have been most successful in reducing relative poverty in recent decades? And how have they done it? Here’s what the picture looks like for twenty affluent nontiny longstanding democracies. The data are from three sources: the Luxembourg Income Study (LIS), considered the most reliable for comparative purposes; the European Union’s Statistics on Income and Living Conditions (EU SILC), which covers recent years for EU countries; and the OECD.

As it turns out, there is hardly any success to explain. In almost every one of these nations the relative poverty rate was no lower in 2007, the peak year of the pre-crash business cycle, than at the end of the 1970s. The only clear exception is Ireland. Denmark also reduced poverty according to the LIS data, but the OECD data suggest little or no change. Portugal is another possibility. A few countries succeeded in reducing relative poverty during certain portions of this period, such as the U.K. in the early 2000s.

What accounts for this near-universal failure?

A relative measure of poverty is essentially a measure of inequality in the lower half of the income distribution. A nation’s relative poverty rate is determined largely by three things: wage inequality among individuals in the bottom half of the distribution, employment inequality among households in the bottom half, and the generosity of the public safety net. The wage distribution has become more unequal in many countries, though by no means all. This owes to a host of developments, including globalization, deregulation of product and labor markets, manufacturing decline, weakening of collective bargaining, and increased immigration of people with language barriers and/or limited job skills. The trend in employment likewise has tended to be inegalitarian, depending on the magnitude and character of the rise in single-adult households, the movement of women into jobs, and government efforts to promote employment. Government transfers have increased in a number of countries, but often only enough to offset the rise in market inequality. And in a few nations transfers have stagnated or decreased. (More discussion here, here, here, here, and here.)

I prefer a focus on absolute incomes and living standards rather than on relative poverty, and that approach yields a very different conclusion about progress in recent decades. Still, the widespread failure of rich countries to make any headway in reducing relative poverty rates is striking.