Table
2 shows the experiment data on rounds played under selected institutions, with the first panel showing tax revenue for the three type distributions. Column
LVTPeriods = 0 shows the average tax revenue in rounds conducted entirely under UPT, while
LVTPeriods = 4 shows the average tax revenue in rounds conducted entirely under LVT. One-half of the rounds were conducted with endogenous tax institutions. If majority voting was allowed and all participants voted with earnings-rationality, then all rounds in
TypeDistA would be in the UPT cell and all rounds in
TypeDistB and
TypeDistC would be in the LVT cells. However, institutions were assigned exogenously in rounds 1 and 2 and could not be changed. So, 6 of 7 observed LVT rounds for
TypeDistA were mandated for LVT; similarly, 6 of 10 UPT rounds for
TypeDistB and 6 of 6 UPT rounds for
TypeDistC were mandated for UPT—all against the types’ earnings-rational tax. The remaining 1 LVT round for
TypeDistA, 4 UPT rounds for
TypeDistB, and 0 UPT rounds for
TypeDistC under earnings-irrational taxes are endogenously selected, i.e., they reflect voting against at least one participant’s earnings-rationality. In addition, the
TypeDistA participants played one period of LVT (
LVTPeriods = 1). In total, 6 of 72 rounds (8.3 percent) played more than one period in an endogenous tax institution against predicted voting; this is 16.7 percent of the endogenous-institution rounds. The deviations could reflect one or more behavioral drivers, such as: (1) errors in earnings-rational choice and (2) political/ethical objections.
Another aspect of earnings-irrational voting is the difference with which it is observed across type distributions. TypeDistC did not deviate when institutions were endogenous. However, deviations happened 16.7 percent of the time for TypeDistA and 33.3 percent for TypeDistB. A reason for this is the number of Type1 participants in each type distribution. Type1 strongly benefits from LVT and had the largest incentives. TypeDistC has three Type1 participants who can use their majority to force the selection of LVT. In contrast, TypeDistA and TypeDistB have no majority with an earnings advantage of that magnitude. Type2 through Type5 have LVT earnings advantages from -40.83 to + 29.19. Type3 is especially close to indifference with an LVT earnings advantages of -18.81. Thus, one expects more uncertainty in the decision making (lower cost of voting against earnings-rationality) with TypeDistA and TypeDistB.
Earnings/Efficiency Results
First, LVT consistently generated more tax revenue, which aligns with model predictions. Table
2 presents the predictions and experimental results on average tax revenue collected. In 42 of 72 periods, average tax revenue was statistically indistinguishable from the prediction. In 16 periods,
TypeDistA averaged slightly more revenue than predicted under UPT, while 14 periods under LVT in
TypeDistB averaged slightly less revenue than predicted. The instances where statistical differences were not found were likely affected by a small N, or number of rounds in which the earnings-irrational tax was endogenously selected or exogenously imposed. The point estimates suggest that UPT tends to generate more revenue than predicted. Conversely, in LVT rounds there is less tax revenue than predicted. That said, the LVT differences are not substantively large. The most important result is that LVT consistently generated far more tax revenue than UPT, as predicted. The predicted UPT tax is 1,708 while LVT averages 2,082, so the predicted tax-revenue advantage for LVT is 22 percent. Although the experiment advantage was slightly less (UPT weighted average 1,759 and LVT averages 2,078), the absolute advantage for LVT of 18 percent (or 319 units) is large.
Second,
AggregatedIndividualEarnings also are higher under LVT. The second panel of Table
2 compares the predicted
AggregatedIndividualEarnings to the experiment results. Rounds under LVT tended to have higher average
AggregatedIndividualEarnings than UPT. Next, Table
2 shows two treatments where
AggregatedIndividualEarnings were statistically indistinguishable from predictions. In 7 of 24 rounds of
TypeDistA the participants played all four rounds in LVT, earning an average of 863 relative to 910 as predicted. Although this point estimate suggests the earnings were lower, there was a low N and no statistical difference was found. The other statistically efficient treatment was
TypeDistC for UPT was also a low-N treatment. Among the remaining four treatment combinations of UPT and LVT, the resulting average earnings were statistically lower than the prediction. In sum, for
TypeDistA, the average round earnings were lower than expected under UPT but not LVT. In
TypeDistB, the average round earnings were lower in both UPT and LVT. In
TypeDistC, the average round earnings were lower than expected under LVT but not UPT. The key points therefore are that observed earnings tended to be lower than predicted and that there is no evidence that participant earnings were less in LVT versus UPT treatments.
The collective efficiency results show that under the modeled conditions LVT is more efficient than UPT. The statistical results for
NetSocietalBenefit—i.e., once the tax revenue is included—are slightly different for
AggregatedIndividualEarnings (third panel of Table
2). For 16 of 24 rounds that
TypeDistA played entirely in UPT,
NetSocietalBenefit produced higher than expected wealth; the slightly higher tax revenue in these rounds more than compensated for the lower participant earnings. Under LVT and the
TypeDistA distribution, however, average
NetSocietalBenefit was indistinguishable from the overall predicted benefit, but the average
NetSocietalBenefit was still 12.7% higher in LVT than UPT.
NetSocietalBenefit under
TypeDistB and
TypeDistC was different than under
TypeDistA. Specifically, UPT rounds resulted in an average
NetSocietalBenefit that was statistically the same as prediction, while LVT rounds had average
NetSocietalBenefit that was statistically less than prediction. The reason for this is that both the average tax revenue and the average participant earnings under LVT tended to be lower than predicted. Under UPT, there was little statistical difference from prediction found on these same two measures, but the point estimate averages were countervailing—i.e., tax revenue had a higher point estimate while participant earnings had a lower point estimate than predicted for UPT. Despite these deviations from predictions, average
NetSocietalBenefit was substantially higher under LVT than UPT (+ 21.1% and + 26.4% for
TypeDistB and
TypeDistC, respectively).
Third, Table
3 offers a controlled econometric test explaining the drivers of
AggregatedIndividualEarnings (Models 1–2); this is a behavioral model derived from the experiment, so we focus on the earning accruing from the participant decisions. We present two models as a robustness check because of collinearity of
Vote with the round measures; however, we focus explanations on model 1, where only
Vote is used to capture the effect.
6 All models have high explanatory power. Starting with LVT does not alter earnings, so there is no anchoring effect. LVT leads to higher earnings and thus efficiency, as predicted.
LVTPeriods has a positive impact, so earnings are higher with more periods under LVT. The net effect of LVT is strongly positive; for instance, four periods of LVT would increase earnings by approximately 220 (at point estimates). The impact of the control variables, capturing heterogeneity and other non-treatment impacts, was as expected. The main effects of
TypeDistA and
TypeDistB were induced in the model to earn less than
TypeDistC, the reserve category, and the results show this. The coefficients magnitudes are roughly similar to the induced value structure.
Table 3
OLS regression explaining experiment private earnings and compactness at the group level
LVTStart | -21.6 (29.1) | -18.5 (29.3) | -0.03 (0.2) | -0.02 (0.2) |
LVTPeriods | 54.2*** (8.7) | 52.9*** (8.8) | 1.0*** (0.1) | 1.0*** (0.1) |
Vote | 125.5*** (39.8) | 86.6 (55.8) | 0.5** (0.2) | 0.4 (0.3) |
TypeDistA | -275.6*** (35.8) | -275.6*** (35.8) | -0.7*** (0.2) | -0.7*** (0.2) |
TypeDistB | -122.5*** (35.8) | -122.5*** (35.8) | -0.02 (0.2) | -0.02 (0.2) |
Vote*TypeDistA | -88.4 (59.4) | -93.1 (59.6) | -0.1 (0.4) | -0.1 (0.4) |
Vote*TypeDistB | -123.8** (51.9) | -125.5** (51.9) | -0.4 (0.3) | -0.4 (0.3) |
Round | | 20.8 (20.9) | | 0.1 (0.1) |
Constant | 1027.8*** (28.2) | 997.7*** (41.4) | 13.0*** (0.2) | 12.9*** (0.3) |
R-squared | 0.86 | 0.86 | 0.95 | 0.95 |
The coefficients on
Vote suggest that voting increases earnings—probably because it allows a group to select its preferred tax. For
TypeDistC, one clearly expects the option to vote would increase private earnings because this distribution has three “LVT lovers,” who can control the majority outcome, and one marginal “LVT lover.” Earnings are higher under LVT for all type distributions, but
TypeDistC earns considerably more under LVT than the other distributions. Having this voting advantage, 4:1, allows
TypeDistC to increase earnings by approximately 125 when allowed to vote. The result on
TypeDistB and voting show that these combined effects tended to produce no extra earnings (b
Vote and b
TypeDistB*Vote roughly cancel each other out). As discussed above,
TypeDistB should have preferred LVT 3:2 and should have earned more under LVT. However, this distribution was the most likely to select the earnings-irrational tax (Table
2 shows the city votes for UPT 4 of 12 times).
TypeDistA tended to earn more when allowed to vote. This was surprising because
TypeDistA was induced to vote for UPT, which would have lower
AggregatedIndividualEarnings. Table
2 showed this group tended to vote too often for LVT: 1 time when
LVTPeriods = 1 and 1 time when
LVTPeriods = 4. This may explain why b
TypeDistA*Vote did not match the hypothesis of a negative effect on earnings.
Compactness Results
The experiment results on spatial impacts collectively show that LVT leads to less sprawl than does UPT, matching the model prediction. The fourth panel of Table
2 compares the experiment results to predictions on the average compactness of the cities, by round. The model predicted that LVT would have cities 3–4 units more compact than the same cities under UPT; however, the experiment results either matched this prediction or exceeded it. Table
2 also shows that in all UPT treatment averages, the city averaged less compactness than predicted. Under LVT, it was less compact in two of three treatments. Together these results suggest a slightly greater tendency for UPT, relative to LVT, to cause sprawl. Comparing the observed outcomes for each type distribution in Table
2 shows that the average point-estimate difference of 3.3–4.7 in
Comp from the tax treatments was roughly the same magnitude as predicted. In
TypeDistC, LVT produced a possibly greater
Comp advantage than expected (
TypeDistC) because the average
Comp under LVT was statistically indistinguishable from the prediction, while the average
Comp under UPT was statistically less than the prediction. As with the efficiency results, these observed differences in behavior from the type distributions likely reflect differences in the magnitude of incentives;
TypeDistC has three
Type1 participants and two marginal types (2 and 3), so a majority have the clearest incentives about where to build and what tax plan to select. In contrast,
TypeDistB has only two
Type1 participants and
TypeDistA has only one
Type1. Collectively, the
TypeDistA and
TypeDistB sessions are more likely to face uncertainty in their decision-making and, thus, one expects the resulting average compactness to be less in line with predictions than
TypeDistC sessions. A more complete causal explanation of these differences is shown in the regression results that explain
CityComp.
Table
3 presents two regressions that explain
CityComp. The collinearity of
Round and
Vote is the same as in the
AggregatedIndividualEarnings regressions. Thus, the following part explains
CityComp Model 1. As with
AggregatedIndividualEarnings, the coefficients on the type distribution controls tend to be significant, but the unexpected result is
TypeDistB in the second model. A reason why the
TypeDistB coefficient lacks significance may be that (as in Table
2) a large number (N = 10) of 24 rounds were played in UPT, with 4 selected by a city against the majority interest. Table
3 shows that LVT leads to more compactness because an additional LVT period (
LVTPeriods) leads to 1 point of
Comp. The prediction (from Table
2) was that, on average, LVT would lead
TypeDistA to 3 more
CityComp points,
TypeDistB to 3.9 more
CityComp points, and
TypeDistC to 4.1 more
CityComp points. The coefficients show a similar treatment effect, where 4 LVT periods lead to roughly 3.3
Comp points for
TypeDistA (4b
LVTPeriods + b
TypeDistA) and about 4 for
TypeDistB (4b
LVTPeriods + b
TypeDistB) and
TypeDistC (4b
LVTPeriods).
The collective behavioral results (Tables
2 and
3) on compactness suggest that participants were either making decisions that resulted in as much or less compactness than predicted; there was no evidence of behavior leading systematically and substantively to more compactness than predicted. There were several situations most likely to produce predicted compactness. First, when the land characteristics have more “LVT lover” types. These settings would be more likely to observe compact building patterns, and this tendency would be higher under LVT. Second, LVT tended to produce more compactness than UPT at levels predicted or at levels slightly exceeding predictions. This provides some experimental evidence to the longstanding claim that LVT does indeed reduce sprawl, and the behavioral evidence suggests that the impact may even be larger than expected.