Saturday, December 20, 2014

What's a Democrat worth?

When straightening up my office at the end of the semester, I ran across a paper by Alan Blinder and Mark Watson that came out this summer.  It points out that since the 1940s the American economy has grown faster under Democratic presidents than under Republicans--a lot faster.   If we restrict it to the complete presidential terms in the data (starting with Truman 1949-53 and ending with Obama's first term), per-capita GDP growth has averaged  12.4% per term under Democrats and 5.7% under Republicans.  

The ranking of individual terms is shown below--the worst performance among Democrats (Obama) is almost equal to the Republican average.

*Truman          21.2%
*Kennedy/Johnson 17.4%
*Johnson         14.9%
Reagan-2         12.2%
*Clinton-2       10.7%
Nixon            10.6%
*Clinton-1       10.5%
Reagan-1         10.3%
GW Bush-1         7.4%
*Carter           6.7%
*Obama            5.5%
Nixon/Ford        4.6%
Eisenhower-2      3.4%
GHW Bush          2.8%
Eisenhower-1      2.3%
GW Bush-2        -2.4

As Blinder and Watson observe, the difference "while hardly a secret, is not nearly as widely known as it should be."   Ironically, the magnitude of the difference is probably part of the reason that it's not well known.  Given that the American economy is large and complex, and that presidents don't have total control over government policy, it's hard to believe that presidents could make this much difference.  So any reasonable person has to say that a lot of it is "luck"--growth varies in mysterious ways, and the Democrats just happened to be there when growth was stronger.  Once you've allowed a lot of it was luck, it's easy to assume that it was all luck.  So even people who know this fact don't talk about it, because they assume that it's just a fluke (that was my first thought when I encountered it in Larry Bartels's Unequal Democracy).

But this is not a reasonable conclusion.  The reasonable conclusion is a compromise--that the observed difference is partly luck and partly "real" (that is, the result of differences in economic policies). More precisely, you can obtain a Bayesian estimate by specifying a distribution that represents your prior beliefs and combining it with the evidence of the data.  For a prior, I took a normal distribution with mean 0 and standard deviation of 1.  That amounts to assuming about a 67% chance that any real effect over a term is less than 1%, 95% chance that it's less than 2%, and almost no chance (less than 1 in a billion) that it's as large as the observed difference of 6.7%.  So this distribution amounts to a strong prior belief that any difference will be small.  Since the normal distribution is symmetrical, the chance of an x% difference in favor of the Republicans is the same as the chance of an x% difference in favor of the Democrats.

Given this prior distribution, after observing the data there is about an 85% chance of a real difference in favor of the  Democrats.  The most likely value is a 0.9% difference in favor of the Democrats.  That doesn't sound like much, but for someone earning $50,000 a year, it would mean they could expect to earn about $450 more at the end of a Democrat's term than at the end of a Republican's term (and given that growth compounds, $450 a year more for the rest of their life).

On the other hand, there's a 15% chance of a real difference in favor of the Republicans--that is, that Republican policies were more effective in producing growth, but because of bad luck they ended up with worse performance.  So the data don't give a definitive answer, but if you're betting, 85% sounds pretty good.

Of course, you don't have to accept my prior distribution, but the point is that luck vs. a real difference isn't all-or-nothing choice.

Wednesday, December 17, 2014

Police, blacks and whites, 1981-2000

A few days ago, I saw an article that referred to a survey question on "confidence in police officers in your community to treat blacks and whites equally."  That question has been asked seven times starting in 1995, most recently in December 2014.  Among whites, confidence rose substantially between the last two times it was asked, September and December 2014, and the level of confidence in December 2014 was the highest ever.  
This led me to look for other questions on the subject--specifically, for questions about police in the country as a whole rather than your own community.  The good news is that there are some, and that they go back to 1981.  The bad news is that they stop at 2000.  The two questions that were asked multiple times:  [agree or disagree that] "these days police in most cities treat blacks as fairly as the treat whites" and "do you think the police in most big cities are generally tougher on whites than on blacks, or tougher on blacks than on whites, or do the police treat them both the same?"  I summarize the results as percent favorable (agree or treat both the same) minus unfavorable.  (The percent saying they were tougher on whites ranged from 0 to 2--I combined them with treat both the same).  

Between 1981 and 2000, there was a substantial move towards seeing treatment as less fair.  The figures are for blacks and whites combined, but given that blacks are only about 12 percent of the population, there must have been a substantial move in this direction among whites.  

Thursday, December 11, 2014

Unions and Management

When looking for questions about unions, I saw one from a 1994 Pew survey:  are they "having mainly a good influence on the way things are going in this country or mainly a bad influence on the way things are going in this country."  The question was never repeated, but it was part of an eight-nation survey.  Here is a summary of the results for each country (percent positive minus percent negative).   The survey recorded opinions in former East Germany and West Germany separately, so I show them both.

Mexico           +32
E. Germany       +25
United States     +5
W. Germany        +5
Spain             +3
Britain            0
France            -3 
Canada           -17
Italy            -21

The United States is fairly favorable by international standards.  I expect that the unfavorable opinions in France and Italy were because strikes were more frequent there, and public opinion is usually negative about strikes (or any kind of disorder).  I'm not sure about Canada--I'd have to check if anything special was going on in 1994.  But American opinion being as positive as West German is a surprise.

The survey also asked the same question about other things, including business executives or management.  The results:

Mexico            +40
Canada            +27
France            +20
E. Germany        +19
W. Germany        +11
United States      +7
Britain            +5
Spain               0
Italy              -3

The United States is not unusual here:  the surprises are Canada and France.

The full report can be found at the Pew Research Center website.  It's not clear if the individual-level data have been preserved.

Saturday, December 6, 2014

Overlooking the obvious-2

The title for my last post was especially appropriate, since I overlooked the obvious question about the popularity of unions.  As Andrew Gelman pointed out in a comment, the Gallup poll has asked people "Do you approve or disapprove of labor unions."  A figure can be found at the Gallup web site:  it shows a substantial decline in approval between the 1950s and late 1970s, and probably some decline between the late 1970s and now.

The question I looked at in my last post showed no clear change between 1952 and the 21st century, so I looked for additional questions on unions that covered a long period of time to see which way they pointed.    There are two questions that go back to the 1940s or 1950s--there is some variation in question wording, but they seem close enough to be roughly comparable

           Good   Bad   DK 
Taking it all in all, would you say unions are a good thing for the country, or a bad thing?
1945   75%   14%   11%  
And, do you think labor unions are good for the general public, or not?
1986   44%   46%   10%
Just in general, do you think labor unions today are good for America or bad for America?
1997   49%   34%  17%
2001   49%   32%  19%
2009   43%   46%  11%

          Agree   Disagree        DK 
Labor unions are very necessary to protect the workingman
1959   73%        15%             11%
Labor unions are necessary to protect the working person
1987   67%        27%               6%
1988   69%        26%               5%
1990   71%        25%               4%
1997   70%        27%               3%
1998   69%        30%               1%
1999   70%        25%               5%
2002   71%        26%               3%
2003   74%        23%               3%
2006   68%        28%               6%
2009   61%        34%               5%
2012   63%        32%               5%

There are also a substantial number of questions asking if people are favorable or unfavorable, but they don't start until the 1985.  I would characterize them as showing some increase in favorable views from the 1980s to the early 2000s and some decline since then, with no definite trend over the whole.  

Putting it together, it seems like there was a substantial decline in support for unions between the 1950s and the 1970s/1980s, some increase until the early 2000s, and some decline more recently.  Returning to my original question of whether unions are popular or unpopular, I'd still say that opinions are somewhat favorable, although not strongly so.

[Data from iPOLL, Roper Center for Public Opinion Research]

Wednesday, November 26, 2014

Overlooking the obvious

Since the midterm elections, there have been a number of stories about "What 'big thing' would reinvigorate the Democratic Party?" to quote the title of one of them.   There seems to be agreement that the problem is that middle-class and working-class incomes haven't been rising, but in the stories I've read no one has raised what seems like an obvious idea:  making it easier for workers to unionize (although Thomas Edsall hints at it).  Back when unions mattered, there was a good deal of research on the "union wage effect," and the consensus was that they raised wages by something like 20% on the average (more for low paid workers and less for high paid workers).  So unionization would help address the problem, and do it  without requiring taxes or spending.  

Is the lack of attention because unions have become so unpopular that it's not worth raising the issue?  In 1952, the Gallup poll asked " In the labor disputes of the last two or three years, have your sympathies--in general--been on the side of the unions or on the side of the companies?" a number of times.  After a long gap, the question was revived in 1999, and was also asked in 2002, 2005, and 2011.  Each time, a plurality said unions--the margin ranged from 3 (37% to 34%) to 18 (52%-34%) percentage points.  The average margin was 9.7% in 1952 and 10.5% in 1999-2011--the difference is not close to being statistically significant.  (There are some ups and downs, but they have no obvious pattern, so I don't show the graph).  So it seems like a pro-union effort would have a reasonable prospect of being popular with the public. 

[data from the Roper Center for Public Opinion Research]

Saturday, November 22, 2014


A recent  piece in the New York Times Jason Weeden and Robert Kuzban tells us that self-interest influences political views.  Along with some uncontroversial examples, there was one that caught my attention:
"Those who do best under meritocracy — people who have a lot of education and excel on tests — are far more likely to want to reduce group-based preferences, like affirmative action."  This didn't sound right to me:  if it were true, universities, especially elite universities, would be centers of opposition to affirmative action.  

Since "affirmative action" can mean a different things to different people, I looked for questions that asked directly about test scores.  There were't many, but I found one in a CBS News/60 Minutes/Vanity Fair survey from 2013.   It asked "Which phrase comes closest to how you would describe the SAT tests that are used for college admissions in the United States:  a successful equalizer, a failed ideal, a waste of time, or a necessary evil"?  The first answer can be regarded as positive, the second and third as negative, and the last one as neutral.  Using this classification, here is the breakdown by education:

                     Pos        Neg    Pos-Neg
less than HS          33   43   23     +10
HS                    25   40   35     -10
Some college          22   44   34     -12
College graduate      21   48   31     -10
Grad School           17   44   39     -22

So people without a high school degree have the most favorable opinions, and people with graduate education are the least favorable.  You get a similar pattern with income:  people with incomes under $30,000 are the most favorable and those with incomes of over $250,000 (admittedly a small group) are most unfavorable.  

Of course, the general point that a lot of opinions have a straightforward relation to self-interest is valid, but as this example shows, there are exceptions.

PS:  I promised an examination of own vote vs. predicted winner in my last post.  Own vote predicted 31 states correctly (that is, there were 31 states in which a majority of the sample said they would vote for X and X won), while the predicted winner actually won in 29 states.  So it was a slight advantage for own vote, but not decisive.    

[Data from the Roper Center for Public Opinion Research]

Monday, November 17, 2014

Post-election coverage

After the election, Justin Wolfers wrote a column saying that questions about who people expected to win were better predictors of election outcomes than questions about who people intended to vote for.  He offered this explanation:  "Asking voters about their expectations allows them to reflect on everything they know about the race — which way they currently intend to vote, how likely they are to vote, whether they’re persuadable, the voting intentions of their friends and neighbors, and their observations about bumper stickers, yard signs, the resonance of a candidate’s message and the momentum they sense in their communities."

You can see how this explanation would appeal to an economist, because it's a parallel to the way that markets work:  combining scattered information in an optimal (or more realistically, pretty good) fashion.  But there's another possibility:  that voters are reflecting what the "experts" are saying, rather than information they have from their own lives.  Even if they're not paying close attention to the campaign, voters are likely to get a sense of what "everybody thinks" will happen.  In 2014, this would mean good predictions, because all the experts were saying that the Republicans would win big, while the polls left more doubt.  But there have been other campaigns in which the the experts were wrong, notably 1948.  Wolfers's explanation says that voters would have called that one correctly, or at least come close.

Did they?  In late September 1948, a Gallup poll asked "regardless of how you, yourself, plan to vote, which candidate do you think will carry this state:  Truman, Dewey, or Wallace?"  25% said Truman, 56% said Dewey, 15% don't know, and the rest Wallace or someone else (presumably Thurmond, who did carry several states in the South).  Of course, the polls were famously wrong in that year, but the survey also asked who they would vote for:  it was 46% for Dewey, 40% for Truman, 4% Wallace, 2% Thurmond.  Given that it was not a large margin for Dewey, it seems like voters' own stated preferences might have been better predictors of how their state would go.  Gallup did record state, so that could be checked, and I will do that in a later post.

PS:  After the election, only 19% said they had expected Truman to win.