I have to move my office hours this week to Thu (11/20) 1:00-3:00p. As always I will be in 103 Marshall College. My office hours will return to their regular time next week.
Archive for the 'research' Category
I posted a revised version of my job market, “Understanding Unemployment Dynamics: The Role of Time Aggregation.” Here is the abstract:
This paper uses weekly data from the Survey of Income and Program Participation (SIPP) to estimate the role of time aggregation in measuring gross labor force flows and unemployment dynamics. Time aggregation is substantial: gross flows estimated from monthly data understate the true number of transitions by 15–24 percent. Time aggregation in both separations to unemployment and accessions from unemployment comoves positively with the business cycle. The effect from time aggregation on separations is roughly offset by its effect on accessions, however, creating no meaningful cyclical bias in measured gross flows or hazard rates. Contrary to claims by Hall (2006) and Shimer (2007), separation hazard rates calculated from the SIPP and the Current Population Survey are strongly countercyclical and remain so after adjusting for time aggregation. In addition, the separation hazard rate contributes fully one-half of the cyclical variance of the steady-state unemployment rate after adjusting for time aggregation.
knzn wonders how many people have lost their jobs in 2008?
According to Barack Obama, 600 thousand Americans have lost their jobs since January. Actually, he’s wrong: something like 20 million Americans have lost their jobs since January. It’s just that most of them found new jobs. Probably the new jobs generally weren’t as good as the ones they lost. And almost certainly, more than 600 thousand of them were unable to find new jobs, because many of the new jobs created were filled by new entrants to the labor force or by people who were already unemployed when the year began.
Like almost everyone else I’ve ever heard, Senator Obama is making the mistake of using a net job loss figure with language that, if taken in its plain sense, clearly implies he is talking about gross job loss. And it seems to me that gross job loss is the appropriate concept: losing your job is a pretty serious bummer, even if you are able to find a new one after a few months.
knzn is right to highlight the distinction between gross and net employment outflows. Obama probably was talking about gross job losses. But the reason presidents talk about “the economy” “creating” so many jobs — never mind that an economy can’t create anything — is because that’s the proper way to interpret the statistic.
It is disingenuous to claim that 20 million workers lost jobs in 2008 without also talking about the 19.4 million persons who found new jobs. It would be equally disingenuous for Bush to claim he “created” 19.4 million jobs in 2008. That brings the discussion back to a net flow of 600 thousand.
Composition effects are large and important, as are the welfare losses from unemployment, but it was the 20 million number that struck me — as too small.
I discussed earlier that about 5 percent of the population (10 million persons) moves into and out of employment every month. Assuming outflows account for roughly half of that, we get 5 million persons a month. Over 8 months that comes to 40 million persons, twice knzn’s estimate.
To be fair, knzn’s figure is a rough estimate based on last year’s data and we all know the risk of projecting current trends into the future — just ask LTCM, Bear Stearns, Lehman Brothers, etc. And I suspect that I’m taking knzn’s forecast more seriously than he does but since I’ve already hauled out the sledgehammer, let’s find that fly.
Continue reading ‘Gross flows on the campaign trail’
Part of my research involves examining the “flow” of persons among three labor force classifications: employed, unemployed, and not in the labor force (NILF). These flows are calculated by observing the change in a person’s labor force status from one month to the next. For example, a person who was unemployed last month but had a job this month would have made a UE transition. The sum of all persons making such transitions that month is called the UE flow.
We use the term gross flows to distinguish such measures from net flows, which are the change in the stock from one month to the next. It is the net change that gets reported in government statistics. For example, if 250,000 persons found a job this month and 100,000 lost a job, the net change is +150,000 persons. The total gross flow, however, is 350,000 persons.
Gross flows are considerably larger than net flows. Over the last 30 years the U.S. economy has added about 150,000 jobs a month (net) on average. During that same period the average gross flow into and out of employment is over 10 million persons a month! To put that figure in perspective, 5.4 percent of the U.S. working-age population moves into and out of employment every month. Accordingly, the net changes reported in the monthly Employment Situation release do not capture the true dynamism in the U.S. labor market.
Although not directly germane to my research, I recently became interested in the long term trend in gross worker flows. The figure below plots the trend in worker flows for 1976-2007. The series shown is the sum of all flows into and out of employment, expressed as a share of population. Since I am interested in only the trend in the series, I remove the substantial month-to-month variation by seasonally adjusting the data and then smoothing the seasonally-adjusted data using a local weighted least squares regression. Shaded bars indicate recessions as determined by the NBER.
There has been a dramatic decrease in gross flows over the past 30 years. This decrease is consistent with evidence from Bleakley, Ferris, and Fuhrer (1999) and Fallick and Fleischman (2004), who also observe declines in gross flows.
In the late 1970s, flows averaged about 5.8 percent of the population a month. This fell more or less steadily throughout the 1980s and early 1990s until bottoming at 5 percent at the end of 1996. Flows grew to just over 5.3 percent a month in 2001 after which they fell off a cliff, stabilizing briefly in 2004-05. By the end of 2007, the total gross flow was below 5 percent of the population. To put a number to this trend, the decline in gross flows means that about 1.7 million fewer persons a month move into and out of employment today compared to 1977.
Identifying an empirical regularity is only a first step in research. Without understanding the causes of this trend it is impossible to draw any meaningful implications from the data. In fact, it is difficult to say whether the secular decline in total gross flows into and out of employment is “good” or “bad”. On the one hand, if the decline represents decreased employment volatility for U.S. workers — increased job stability — then it may be a positive development. On the other hand, if the observed decline in gross flows results from decreasing allocative efficiency — labor market “sclerosis” — then the trend may be worrisome. Other possible explanations include “job lock,” where employees cannot easily change jobs because of employer-provided health insurance, and increased efficiency in employer-employee job matching, resulting in fewer low-quality matches and thus less job turnover.
The examples above show that both explanations and implications can be conflicting and contradictory. This is why economists write models. Also why Truman wanted a one-armed economist.
I am presenting my research in progress on endogenous labor force participation at this week’s macro lunch seminar. The talk is Wednesday (30 Apr) from 12:30-13:30 in 244 Sequoyah.
Today I present my research on time aggregation bias at the GSRS. The talk is cleverly titled “Estimating Time Aggregation Bias”. The seminar is at 10:00 in 244 Sequoyah.
I am presenting several papers on labor force participation in matching models at this week’s macro lunch seminar. I will be discussing Blanchard and Diamond (1990, BPEA no. 2), Garibaldi and Wasmer (2005, Journal of the European Economic Association 3(4)), and Haefke and Reiter (2006, IZA discussion paper 2029).
I will also present some new data on labor force participation and the business cycle. The seminar is Wednesday (22 Feb) from 12:30-13:30 in 244 Sequoyah.
I created a new page with automated “real-time” graphs of several economic time series. It draws on publicly-available data on interest rates, prices, durable goods and retail sales. The graphs are updated as new data become available.
My new paper with Shigeru Fujita and Garey Ramey, The Cycality of Worker Flows: New Evidence from the SIPP, has been released. Read more or download a copy on my research page.
I am hosting a review session for problem set 2 tonight from 17:00-18:50 in 105 Center Hall.