From an entirely unexpected quarter, comes a story of the shortcomings of computer modelling, in this case in the America's cup. It is a great example of how models reflect the biases of their authors. In this case, the author assumed that the fastest upwind path was the shortest path (ie with the shallowest possible tacks). It turns out that with the changing technology of boats, particularly the hydrofoil, a longer but higher velocity path was more optimal, but the model refused to consider that solution because it was programmed not to.
Archive for February 2014
Please check out my Forbes post today. Here is how it begins:
Last night, the accumulated years of being called an evil-Koch-funded-anti-science-tobacco-lawyer-Holocaust-Denier finally caught up with me. I wrote something like 3000 words of indignation about climate alarmists corrupting the very definition of science by declaring their work “settled”, answering difficult scientific questions with the equivalent of voting, and telling everyone the way to be pro-science is to listen to self-designated authorities and shut up. I looked at the draft this morning and while I agreed with everything written, I decided not to publish a whiny ode of victimization. There are plenty of those floating around already.
And then, out of the blue, I received an email from a stranger. Last year I had helped to sponsor a proposal to legalize gay marriage in Arizona. I was doing some outreach to folks in the libertarian community who had no problem with gay marriage (after all, they are libertarians) but were concerned that marriage licensing should not be a government activity at all and were therefore lukewarm about our proposition. I suppose I could have called them bigots, or homophobic, or in the pay of Big Hetero — but instead I gathered and presented data on the number of different laws, such as inheritance, where rights and privileges were tied to marriage. I argued that the government was already deeply involved with marriage, and fairness therefore demanded that more people have access to these rights and privileges. Just yesterday I had a reader send me an email that said, simply, “you changed my mind on gay marriage.” It made my day. If only climate discussion could work this way.
So I decided the right way to drive change in the climate debate is not to rant about it but instead to continue to model what I consider good behavior — fact-based discussion and a recognition that reasonable people can disagree without that disagreement implying one or the other has evil intentions or is mean-spirited.
This analysis was originally published about 8 years ago, and there is no longer an online version. So for fun, I thought I would reproduce my original thought experiment on climate models that led me to the climate dark side.
I have been flattered over time that folks like Matt Ridley have picked up on bits and pieces of this analysis. See it all here.
Apparently it is some kind of amazing new insight or quasi-scandal that the Fed seems to care more about inflation than unemployment, at least as measured by the language of its meeting notes.
Call me crazy, but the Fed's job is to manage the currency and money supply, not to manage employment or the broader economy. I have always assumed that it was understood by all that keeping the value of money stable (ie fighting inflation) was the Fed's priority ahead of other economic issues. What am I missing here?
via Maggies Farm
In addition, some smart people are saying the WhatsApp acquisition for a bazillion dollars makes sense, but I can't help feeling like it is the late 90's all over again.
update: Apparently unlike most all other major online advertisers, Facebook terms and conditions do not allow 3rd party click audits.
The only reason people like Michael Moore or Tom Harkin can get away with singing praises of Cuban socialism is because most Americans can't go visit and see for themselves. By keeping Cuba off-limits, we are doing the communists' work for them by allowing them to provide cherry-picked videos and stories through useful idiots that have zero bearing on the true life of the average person in Cuba.
When I was in high school, there was a dating ritual in which the guy (ie me) went to pick up the girl at the girl's house. The girl was never ready, so the guy was forced into an awkward (particularly on the first date) conversation with the girl's dad.
Apparently, this sort of dating ritual is gone, at least at our school and in my family. As my daughter gets closer and closer to leaving high school, it finally struck me last night that I may never get to enjoy the payback of being the "dad" in this ritual. And I was all ready, too. I never use my shotgun any more but I keep it around solely in the hope of having it out on the table for cleaning when my daughter's date comes over. Now I fear I will be denied this small joy.
(Of course, the fact that I have communicated my fantasy of cleaning my shotgun on my kitchen table when my daughter's dates come over may have something to do with my daughter structuring her social life such that boys never come over. Corollary to Heisenberg: You cannot discuss a fantasy without disturbing it).
We have never really been able to look at trees as the agricultural crop that they are. I am reminded of this fact from this forest watch site at Google, which purports to track deforestation around the world.
I have no problem calling activity in the Amazon where old growth is logged out in a tragedy of the commons "deforestation". But the map is odd to me in the Southeast US. While there likely is some reduction in forested lands around urban areas, overall the US has actually been increasing its forest cover since the early 1900's. But the Google map of the southeast shows lots of forest "loss". It also shows about as much forest "gain". (red is loss, blue is gain, click to enlarge)
Why is that?
Of late, I have spent a lot of time in the southeast and what I have observed are a lot of private forest lands that are harvested for timber. One plot is harvested one year, and fast growing trees are replanted. Then the next year a neighboring plot is harvest, etc, until it all starts over with the first plot. In a large sense this is no different than any other kind of farming, just with a 15 year growing season instead of a one-summer season.
Calling harvested lands in this area "forest loss" and new growth "forest gain" makes about as much sense as calling land held fallow for a season in Iowa as "corn loss" and newly planted land as "corn gain." There is a difference between farming trees and strip-mining them that gets lost in this data.
My new column is up at Forbes.com, and asks why we fetishize capital gains over regular income
Let's consider two investors. Investor A buys a piece of land and builds a campground on it, intending to run the campground for decades. Investor A gets her return on investment from the profits each year running the campground, profits that are taxed as regular income (Full disclosure: In my business life, I am essentially investor A).
On the other hand, Investor B buys the same piece of land and builds the same campground on it, but in about a year Investor B sells the newly developed facility, making a profit on the sale over his original investment. Investor B likely will pay taxes on this gain at reduced capital gains tax rates.
But why? When Investor B sold the property, the price he got was probably something like the present value of the expected cash flows from operating the campground. Both Investor A and B created essentially the same value., but Investor B took the value as a single lump sum rather than as a stream of income over time. Why is Investor B's approach preferred in the tax code? Or, stated another way, why does the tax code favor asset flipping over long-term operations?
How Did Obamacare Authors Ever Fool Themselves Into Believing They Were "Bending the Cost Curve" With These Kind of Incentives?
I guess I never really paid much attention to how the Obamacare "risk corridors" work. These are the reinsurance program that were meant to equalize the risks of various insurers in the exchanges -- but as exchange customers prove to be less healthy than predicted, they are more likely to become a government subsidy program for insurers.
I never knew how they worked. Check out the incentives here:
According to the text of Obamacare, the health law's risk corridors—the insurance industry backstop that’s been dubbed a bailout—are only supposed to last through 2016. For the first three years of the exchanges, insurers who spend 3 percent more on health costs than expected will be reimbursed by the federal government. It’s symmetrical, so insurers who spend less will pay in, but there’s no requirement that the program be revenue neutral
So what, exactly, are the incentives for cost control? If you lose control of your costs, the government simply pays for the amount you overspent. Combine this with the fact that Obamacare puts caps on insurer non-patient-cost overhead spending, and I don't think you are going to see a lot of passion for claims management and reduction. Note after a point, excess claims do not hurt profits (via the risk corridor) but more money spent on claims reduction and management does reduce profits (due to the overhead caps).
Postscript: There is one flaw with my analysis -- 3% is a LOT of money, at least historically, for health insurers. Why? Because their margins are so thin. I know this will come as a surprise with all the Obama demonization of insurance profits, but health insurers make something like 3-5% of revenues as net income. My Boston mother-in-law, who is a very reliable gauge of opinion on the Left, thinks I am lying to her when I say this, even when I show her the Google finance pages for insurers, so convinced is she by the NYT and PBS that health insurer profits consume a huge portion of health care spending.
All that being said, I am pretty sure if I were an insurer, I could raise prices slightly, cut back on claims overhead, and make a guaranteed profit all while the government absorbs larger and larger losses.
Looking at this map of state licensing regimes (darker is more onerous, with AZ being the worst), it is hard to correlate with states being Republican or Democrat. That doesn't surprise me, because I have always thought the urge to restrict competition and protect incumbents has always been a bipartisan enterprise.
So I sat and thought for a minute about my home state of AZ. Why is it the worst? We have a pretty good libertarian history here, from Goldwater onwards. We have at least one fairly libertarian Senator (Jeff Flake). So what is the deal?
My hypothesis is that it is related to immigration. The same majority Republican legislators who are generally open to free markets simultaneously have an incredible fear and loathing of immigration. Perhaps our onerous business licensing regime is driven by nativists wanting to protect themselves from competition by new immigrants, immigrants who would struggle to compete onerous licensing requirements?
So what does this map look like vs. immigrant population density? Via Wikipedia, here are the states on density of Hispanics
Hmm, we might be getting somewhere, but its not a perfect fit. So instead, let's hypothesize that business licensing is aimed at non-white, non-hispanic groups in general (similar to early justifications for the minimum wage as a way to keep black workers migrating from the south out of traditionally "white" jobs). I cannot get it by state, but the map below by county looks pretty dang similar to the licensing map. Areas in blue have above average percent of non-whites, red is below average.
Not a perfect fit certainly (one would expect Texas to be more onerous), but perhaps close enough to treat the hypothesis seriously. I had always thought that I would be the last one to play the race card in a policy analysis, but business licensing tends to have an inherently base motive (protect one group from competition from another group) that is pretty easy to square with racial and ethnic fear.
Want to Make Your Reputation in Academia? Here is an Important Class of Problem For Which We Have No Solution Approach
Here is the problem: There exists a highly dynamic, multi- multi- variable system. One input is changed. How much, and in what ways, did that change affect the system?
Here are two examples:
- The government makes a trillion dollars in deficit spending to try to boost the economy. Did it do so? By how much? (This Reason article got me thinking about it)
- Man's actions increase the amount of CO2 in the atmosphere. We are fairly confident that this has some warming effect, but how how much? There are big policy differences between the response to a lot and a little.
The difficulty, of course, is that there is no way to do a controlled study, and while one's studied variable is changing, so are thousands, even millions of others. These two examples have a number of things in common:
- We know feedbacks play a large role in the answer, but the system is so hard to pin down that we are not even sure of the sign, much less the magnitude, of the feedback. Do positive feedbacks such as ice melting and cloud formation multiply CO2 warming many times, or is warming offset by negative feedback from things like cloud formation? Similarly in the economy, does deficit spending get multiplied many times as the money gets respent over and over, or is it offset by declines in other categories of spending like business investment?
- In both examples, we have recent cases where the system has not behaved as expected (at least by some). The economy remained at best flat after the recent stimulus. We have not seen global temperatures increase for 15-20 years despite a lot of CO2 prodcution. Are these evidence that the hypothesized relationship between cause and effect does not exist (or is small), or simply evidence that other effects independently drove the system in the opposite direction such that, for example, the economy would have been even worse without the stimulus or the world would have cooled without CO2 additions.
- In both examples, we use computer models not only to predict the future, but to explain the past. When the government said that the stimulus had worked, they did so based on a computer model whose core assumptions were that stimulus works. In both fields, we get this sort of circular proof, with the output of computer models that assume a causal relationship being used to prove the causal relationship
So, for those of you who may think that we are at the end of math (or science), here is a class of problem that is clearly, just from these two examples, enormously important. And we cannot solve it -- we can't even come close, despite the hubris of Paul Krugman or Michael Mann who may argue differently. We are explaining fire with Phlogiston.
I have no idea where the solution lies. Perhaps all we can hope for is a Goedel to tell us the problem is impossible to solve so stop trying. Perhaps the seeds of a solution exist but they are buried in another discipline (God knows the climate science field often lacks even the most basic connection to math and statistics knowledge).
Maybe I am missing something, but who is even working on this? By "working on it" I do not mean trying to build incrementally "better" economics or climate models. Plenty of folks doing that. But who is working on new approaches to tease out relationships in complex multi-variable systems?
It used to be that updates of software products were something to look forward to. I used to be a bleeding edge guy who, like as not, was using beta versions of most software. Now I avoid updates and upgrades like the plague, particularly since companies like Apple make it virtually impossible to roll back any software update. The four products that have scared me off of upgrades altogether are:
- Windows 7 to Windows 8
- Old versions of Office to the new versions with the stupid toolbars rather than menus where I still can't find what I want all the time. On a bunch of my computers I still use Office 2002 and 2003 and it works just fine.
- Most all itunes updates, particularly 10 to 11 which has done nothing but make critical options harder to find and make the platform, at least on Windows, less stable. I am told people are having major difficulty with the 11.3 to 11.4 update
- iOS 6 to iOS 7, which decreased battery life without adding any real user features. So glad I still have not upgraded, though I am sure I will have to soon.
And don't even get me started on software like windows 8 and most of the recent Adobe products that require some sort of user login to even use the product at all.
The other day I had a little fun with Bing's search results on Windows 8 problems. But this seems much more serious. From a reader:
That’s Microsoft’s response to new revelations that the search engine is censoring Chinese searches in the United States — not just in China. Searches on Chinese topics in the U.S. now produce markedly different search results than Google, results that mimic those in China. China broadly censors the Internet, blocking topics like the Dalai Lama and Tiananmen Square.
The censorship blog Greatfire.org was the first to point out that Bing’s search results display information propagated by Chinese authorities. A Chinese language search in Bing for the Dalai Lama (达赖喇嘛 in Chinese) produces two results from China’s Wikipedia (Baidu Baike) and one from the state-owned television station CCTV. In Google, the same search returns two Wikipedia entries and the Dalai Lama’s official site.
Even more shocking, a search for the anti-censorship software FreeGate produces the result: “Due to restrictions on Chinese laws and regulations, we removed the results of these search terms. For more information, see here.”
Microsoft responded to a request from Charlie Smith’s Greatfire to explain the discrepancy. At first, the software juggernaut replied: “We’ve conducted an investigation of the claims raised by Greatfire.org. First, Bing does not apply China’s legal requirements to searches conducted outside of China. Due to an error in our system, we triggered an incorrect results removal notification for some searches noted in the report but the results themselves are and were unaltered outside of China.”
But after finding the “due to Chinese laws and regulations” search result, Microsoft replied: “Thanks for your inquiry. We have no comment on this topic.”
Much more detail at the link, with examples and screenshots
Kevin Drum argues that rules preventing voting in many states by felons are unfair. After all, we don't deny them their first amendment rights for having been in prison, right?
Well, unlike Drum, I put voting further down the list of essentials for a free society, well behind property rights and the rule of law (see here and here). If I wanted to get worked up about post-incarceration loss of rights, I would address the increasingly draconian post-incarceration restrictions on those convicted of even trivial "sex" crimes (treating 17 years olds that sent a nude selfie the same as a rapist).
However, let's talk voting. Yes we do not deny ex-cons their first amendment rights. But we do deny them their second amendment rights. So I offer this compromise:
I propose this bipartisan compromise: Voting and gun ownership rights for convicted felons should be identical. Set them wherever you think is fair, but make them consistent. I am not sure this is really a very fair comparison -- after all, a politician can do a heck of a lot more damage than a gun -- but as I said, I am willing to compromise.
Once we equate making people feel bad with actually attacking them, free expression is basically obsolete, since anything a person does, makes or says could be interpreted as abuse.
Beyond the general amazing sight of feminists acting like Victorian women with the vapors rather than strong, confident human beings, I am still amazed at this interpretation of the art as somehow representing a male threat. Perhaps this is one area where the campus is poorer for the lack of male voices. I can't imagine there are many men who see this statue as anything other than a representation of fear and vulnerability and helplessness. Seriously, does anyone consider sleepwalking at school in your tighty whities as anything but a bad dream? If you had showed me this statue before all the brouhaha and asked me if it was more threatening to men or women, I would have answered "men" without a second thought.
This is just sick, via Fox News and Bryan Preston
Consider what administration officials announcing the new exemption for medium-sized employers had to say about firms that might fire workers to get under the threshold and avoid hugely expensive new requirements of the law. Obama officials made clear in a press briefing that firms would not be allowed to lay off workers to get into the preferred class of those businesses with 50 to 99 employees. How will the feds know what employers were thinking when hiring and firing? Simple. Firms will be required to certify to the IRS – under penalty of perjury – that ObamaCare was not a motivating factor in their staffing decisions. To avoid ObamaCare costs you must swear that you are not trying to avoid ObamaCare costs. You can duck the law, but only if you promise not to say so.
As I have written about before, our company closed some California operations in December and laid off all the employees. As with most business closures, we had multiple reasons for the closure. The biggest problems were the local regulatory issues in Ventura County that made it impossible to make even simple improvements to the facilities. But certainly looking ahead at costs soon to be imposed due to looming California minimum wage increases and the employer mandate contributed to the decision.
So, did I fire the workers over Obamacare? If Obamacare were, say, 10% of the cause, would I be lying if I said I did not fire workers over Obamacare? Or does it need to be 51% of the cause? Or 1%? Or 90%. Business decisions are seldom based on single variables. I am just exhausted with having my life run by people whose only experience with the real world was sitting in policy seminars at college.
Update: The actual effect of this will not likely be to change business behavior, but change how they talk about it. Worried that there will be too many stories next election about job losses due to Obamacare, the Administration is obviously cooking up ways not to limit the job losses, but to limit discussion of them.
Why Do We Manage Water Via Command and Control? And Is It Any Surprise We Are Constantly Having Shortages?
In most commodities that we consume, market price signals serve to match supply and demand. When supplies are short, rising prices send producers looking for new supplies and consumers to considering conservation measures. All without any top-down intervention by the state. All without any coercion or tax money.
But for some reason water is managed differently. Water prices never rise and fall with shortages -- we have been told in Phoenix for years that Lake Powell levels are dropping due to our water use but our water prices never change. Further, water has become a political football, such that favored uses (farmers historically, but more recently environmental uses such as fish spawning) get deep subsidies. You should see the water-intensive crops that are grown in the desert around Phoenix, all thanks to subsidized water to a favored constituency. As a result, consumers use far more water than they might in any given year, and have no natural incentive to conserve when water becomes particularly dear, as it is in California.
So, when water is short, rather than relying on the market, politicians step in with command and control steps. This is from an email I just received from state senator Fran Pavley in CA:
Senator Pavley said the state should consider measures that automatically take effect when a drought is declared to facilitate a more coordinated statewide response.
“We need a cohesive plan around the state that recognizes the problem,” Pavley said at a committee hearing. “It’s a shared responsibility no matter where you live, whether you are an urban user or an agricultural user.”
Measures could include mandatory conservation, compensation for farmers to fallow land, restrictions on the use of potable water for hydraulic fracturing (“fracking”), coordinated publicity campaigns for conservation, increased groundwater management, and incentives for residents to conserve water. Senator Pavley noted that her hometown Las Virgenes Municipal Water District is offering rebates for customers who remove lawns, install rain barrels or take other actions to conserve water.
Pavley also called for the state to create more reliable, sustainable supplies through strategies such as capturing and re-using stormwater and dry weather runoff, increasing the use of recycled water and cleaning up polluted groundwater basins.
Note the command and control on both sides of the equation, using taxpayer resources for new supply projects and using government coercion to manage demand. Also, for bonus points, notice the Senator's use of the water shortage as an excuse to single out and punish private activity (fracking) she does not like.
All of this goes to show exactly why the government does not want a free market in water and would like to kill the free market in everything else: because it gives them so much power. Look at Ms. Pavley, and how much power she is grabbing for herself with the water shortage as an excuse. Yesterday she was likely a legislative nobody. Today she is proposing massive infrastrure spending and taking onto herself the power to pick winners and losers (farmers, I will pay you not to use water; frackers, you just have to shut down). All the winners will show their gratitude next election cycle. And all the losers will be encouraged to pay protection money so that next time around, they won't be the chosen victims.
Faulting the IRS for attempting to “unilaterally expand its authority,” the D.C. Circuit today affirmed a district court decision tossing out the agency’s tax-preparer licensing program. Under the program, all paid tax-return preparers, hitherto unregulated, were required to pass a certification exam, pay annual fees to the agency, and complete 15 hours of continuing education each year.
The program, of course, had been backed by the major national tax-return preparers, chiefly as a way of driving up compliance costs for smaller rivals and pushing home-based “kitchen table” preparers out of business. Dan Alban of the Institute for Justice, lead counsel to the tax preparers challenging the program,called the decision “a major victory for tax preparers—and taxpayers—nationwide.”
The licensing program was not only a classic example of corporate cronyism, but also of agency overreach. IRS relied on an 1884 statute empowering it to “regulate the practice of representatives or persons before [it].” Prior to 2011, IRS had never claimed that the statute gave it authority to regulate preparers. Indeed, in 2005, an IRS official testified that preparers fell outside of the law’s reach.
Perhaps a first indication that the Obama Administration strategy to pack the DC Circuit with Obama appointees may not necessarily protect his executive overreach.
PS - you gotta love the IJ.
PPS - The IRS justified its actions under "an obscure 1884 statute governing the representatives of Civil War soldiers seeking compensation for dead horses"
People like to compare what Krugman writes today in his political hack era with what he wrote in his real economist era. But this time I do not have to look that far back.
On February 5 and On February 6, Krugman essentially agrees with the OMB review of Obamacare effects on employment, saying that the health care subsidies for lower-income workers would cause millions to work less by reducing the incentive to work, which he called "a good thing." More here.
On February 9, Krugman returns to a theme he has been hitting on for some weeks now, calling the Republicans anti-science, mean-spririted, etc. for actually believing that unemployment benefits might reduce employment by reducing the incentive to work. And here is what he wrote on the topic on December 8:
The view of most labor economists now is that unemployment benefits have only a modest negative effect on job search — and in today’s economy have no negative effect at all on overall employment. On the contrary, unemployment benefits help create jobs, and cutting those benefits would depress the economy as a whole.
Yes I understand the shape of the subsidy patterns with income are different, but good God man you cannot reasonably argue that the labor supply curve is sensitive to means-tested government subsidies for one program but not at all for another without a heroic analysis that I cannot imagine and Krugman has not supplied.
Don't let Amazon's placement of it in the "craft" section fool you. E-6000 is the best all-purpose, stick-any-two-arbitrary-things-together adhesive I have ever found.
I made my daughter a Christmas present which was a reproduction of the painting in the Disney Haunted Mansion where the man in the picture slowly turns to a skeleton. I will post a build report at some time, but I had to anchor a heavy computer monitor to a wood box and an Ikea plastic frame, and E-6000 welded the whole thing together. I also have used it recently to glue studs to a concrete floor to support a cabinet and to put a rubber weir under my garage door. It takes a day to cure, and will not go on thin and sometime can be messy, but it makes an awesome bond. I almost never touch epoxy or Liquid Nails any more.
Update: I know Gorilla Glue has its adherents. The problem is that it expands so much (it kind of foams), it is really hard to control and get good results, at least in my opinion. Neither of these replace ACC when you need to bond something fast or when you want your fingers stuck together all day.
This is a pretty amazing chart from Jed Graham and IBD which I have annotated a bit
Note first that the diversion between high and low-wage** industries did not occur during the recession, and in fact through the recession the two groups tracked each other pretty closely until early 2010. Then, in early 2010, something made the two lines start to diverge and in 2012-2013 they really went in opposite directions.
Well, my suggestion for the "something" is Obamacare. In March 2010, the PPACA was passed. Looking at the jobs data, one can date the stall in the economic recovery almost precisely from the date the PPACA was passed (e.g. here).
The more important date, though, is January 1, 2013. This is a date that every business owner was paying attention to at the time but which seems entirely lost on the media. All the media was focused on the start-date of the employer mandate on January 1, 2014. Why was the earlier date important? Let's go back in time.
At that time, the employer mandate had yet to be delayed. The PPACA and IRS rules in place at the time called for a look-back period in 2013 where actual hours worked for each employee would be tracked to determine whether the employee would classified as full or part-time on the Jan 1, 2014 start date. So, if a company wanted to classify an employee as part-time at the start of the employer mandate (and thus avoid penalties for that employee), that employee needed to be converted to part-time as early as possible, preferably before 2013 even started and at worst by mid-year 2013 [sorry, I typo-ed these dates originally].
Unlike the government, which apparently waits until after the start-up date to begin building large pieces of major computer systems, businesses often tackle problems head on and well in advance. Faced with the need to have employees be working 29 hours or less a week in the 2013 look-back period, many likely started making changes back in 2012. Our company, for example, shifted everyone we could to part time in the fourth quarter of 2012. I know from talking to the owners of several restaurant chains that they were making their changes even earlier in 2012. One employee of mine went to Hawaii in October of 2012 and said that all the talk among the resort employees was how they were getting cut to part-time over Obamacare.
Yes, the employer mandate was eventually delayed, but by the time the delay was announced, every reasonably forward-looking company that was going to make changes had already done so. Having made the changes, there is no way they were going to switch back, and then back yet again when the Administration finally stumbles onto an actual implementation date.
If this chart gets any traction over the next few days, expect to see a lot of ignorance as PPACA defenders claim that the fall in low-wage work hours can't possibly have anything to do with the PPACA because the employer mandate has not even started. Now you know why this argument is wrong. The PPACA, and associated IRS implementation rules, drove companies to convert full-time to part-time jobs as early as 2012.
Usual warning: Correlation is not causation. However, I will submit that I was predicting exactly this sort of result years before it occurred. This is not a spurious correlation that is ex post facto blamed on whatever particular bete noir I might have. I and many other predicted that Obamacare would drive down work hours per week in lower-wage industries, and now having seen exactly that correlated with key Obamacare dates, it is not going to far to hypothesize a connection.
** Why could low-wage industries be impacted more than high-wage? Two reasons. One, low-wage industries are far less likely to offer a full Obamacare-compatible health plan to employees than high wage industries. Second, the fixed penalties ($2000 and $3000 per employee) for lack of insurance plans are obviously a far higher percentage of the total pay in low-wage vs. high-wage industries. A penalty that is 15% of annual pay is much more likely to cause employers to shift or reduce work than a 3% penalty.
Today I have yet another person with a full disability settlement (e.g. from Social Security) telling me that they are fully capable of working and pestering me to hire them. The rub is that paying them any money would endanger their disability payments, so they ask me to pay the money to someone else (husband, child) or to pay them off books in cash. Essentially, they are asking me to violate the law in order the help them violate the law.
Why would I take this risk? Last year I had 21,000 people sign up on a mailing list looking for work.
Perhaps I am somehow an outlier because I hire so many older folks, but I get dozens of request like this a year. You can't convince me that the disability system is not broken.