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v0.28.9 — This text is under construction. The structure of the theory, the propositions, and the empirical conclusions may all change. Overview

Chapter 16
Evidence From the Corporate Statistics: κ and CCC Across Firms

16.1 Position of this chapter

The κ and CCC defined in Part I are applied to the industry and size tabulations of the Financial Statements Statistics of Corporations by Industry. Two cross-sections are taken.

The cross-section by size examines how the direction of credit corresponds to size class. Section 6.3 writes the credit layer as an image of bargaining power; if so, smaller firms should be the providers of credit.

The cross-section over time examines whether change in CCC indicates the state of an industry — whether demand is tight. But “the industry is hot” is not one-dimensional, and CCC touches only one of its axes. That is settled in the next section.

To state the conclusion first, both implications failed: the direction of credit has the opposite sign, and the leading property vanished entirely.

16.2 Hot and cold are not one-dimensional

Before measuring, what is to be judged must be settled. The g⋆ = (m + d − I∕r)∕CCC of (5.6) consists of two separate axes, a numerator expressing profitability and a denominator expressing liquidity. Likewise, an industry being hot and entering it being profitable are different things.

Even where demand is tight, if an intermediary controls access to that demand, the surplus does not remain with the entrant. Chapter 17 finds the price of T𝑎𝑐𝑞 reaching 20 points. Two axes are therefore needed.

Axis Indicator

Measurability

Tightness of demand change in κ, growth rate

measurable in the corporate statistics

Ease of taking surplus the price of T𝑎𝑐𝑞, concentration of ϕ𝑏𝑎𝑟𝑔

no cross-industry indicator exists

Table 16.1: Two axes for judging hot and cold, and their measurability.

Only the former can be handled here. Of the four quadrants, up and down can be distinguished but not left and right.

Remark 16.1 (Why the horizontal axis cannot be measured, structurally). This is not a shortage of sources but an asymmetry of classification.

Industry classifications are cut from the entrant’s point of view: a firm in information and communications is tabulated there. But intermediaries span industries. A payment platform belongs to information and communications while intermediating for retail, food service, travel and education alike.

Summing ϕ𝑏𝑎𝑟𝑔intermediary by industry therefore only books the intermediary’s take in one industry, and which industry it was taken from cannot be recovered. In the notation of Section 2.6, an intermediary is one of the party indices i; it is neither a type of Φ nor an industry.

The entrant’s margin already reflects the leakage to intermediaries, but whether it is due to that leakage or to something else cannot be separated from industry aggregates. Separating it needs a cross-section seen from the intermediary side, and why that is unavailable is set out in Section 17.5.1.

Theoretical quantities in this chapter
κC Eq. (3.2)

DSO; 35–71 days by size

κS Eq. (3.2)

−DPO; DPO is 21–44 days by size

W,r Chapter 5

working capital, sales

CCC Eq. (5.1)

37 days for all industries; 5–210 days by industry

g⋆ Eq. (5.6)

illustrated with assumed values, m not obtained here

m Chapter 5

not obtained

Table 16.2: Theoretical quantities in this chapter.

16.3 Data source

The time-series data of the Financial Statements Statistics of Corporations by Industry (e-Stat table 0003060791) were used. It is a designated statistical survey under the Statistics Act, and the annual survey covers all profit-making corporations. Capital classes extend down to below two million yen, so the bias towards listed companies raised in Section 12.9 does not arise.

Six items were obtained: notes receivable, accounts receivable, finished goods and merchandise, notes payable, accounts payable and sales. Section 16.10 adds inventory (period end) for a reconciliation. Raw figures rather than ready-made turnover indicators were obtained so that the definitions of Chapter 5 could be applied directly, without depending on whether the statistic’s own denominator is sales or cost of sales.

DSO = notes receivable + accounts receivable sales × 365 (16.1) DPO = notes payable + accounts payable sales × 365 (16.2) CCC = DSO + DIO −DPO (16.3)

These express the credit positions of (3.2) in days. That is,

κC ↔DSO,κS ↔−DPO,∑ iκi ↔DSO −DPO (16.4)

A firm with ∑ ⁡ iκi > 0 is a provider of credit. The working capital of (5.1) is W = (DSO + DIO −DPO) × r∕365.

16.4 Size and the direction of credit

16.4.1 The implication tested

Registered implication: the smaller the size class, the larger DSO −DPO; that is, smaller firms are the providers of credit.

The ground was the claim of Section 6.3 that the credit layer is an image of bargaining power: small firms without bargaining power should be the ones kept waiting for payment.

16.4.2 Result

Size (capital) DSO DIO DPO DSO−DPO
1bn yen and over 71 20 44 27
100m – 1bn 61 20 47 15
50m – 100m 47 20 37 10
20m – 50m 49 15 39 10
10m – 20m 53 18 35 18
Under 10m 35 12 21 14
Table 16.3: DSO, DIO, DPO and DSO−DPO by capital class.

All industries excluding finance and insurance, FY2024, in days

Figure 16.1: DSO and DPO by capital class (all industries, FY2024). Both are short for the small classes.

The implication is rejected; the sign is the opposite. Firms of 1bn yen and over sit at 27 days and those under 10m at 14, so large firms are the providers of credit. The ordering is consistent over the ten years 2015–2024, and the large-firm figure has in fact widened from 19 to 27 days.

16.4.3 The error in the reasoning

The error can be located. It was overlooked that DSO and DPO both move.

Small firms are kept waiting on receivables (DSO works against them). But at the same time they are not trusted by suppliers either and cannot stretch payables. As Figure 16.1 shows, the DPO of the under-10m class is 21 days, less than half the 44 of firms of 1bn and over.

A lack of bargaining power acts on both sides: collection is slow but payment is fast. On balance, weak bargaining power does not appear in the net credit position.

Proposition 16.2 (Extending credit requires capital). A net provider of credit, that is a party with ∑ ⁡ iκi > 0, satisfies E > A.

Proof. By the fundamental inequality of Proposition 5.2, W ≤ E − A. Since W = ∑ ⁡ iκi + Inv with Inv ≥ 0, ∑ ⁡ iκi > 0 implies W > 0 and hence E − A > 0. □

Under the E ≈ 0 of Chapter 8, the requirement was the reverse, κ < 0 (Corollary 5.4). Tolerating collection as long as a DSO of 71 days is possible because there is capital behind it.

16.4.4 The sign splits by industry

Industry 1bn and over Under 10m Difference
Information and communications 64 15 +49
Construction 67 19 +48
All industries 27 14 +13
Manufacturing 26 24 +2
Employment placement and dispatch 24 25 −1
Retail −16 6 −22
Table 16.4: DSO−DPO by industry, comparing capital of 1bn yen and over with under 10m. Only retail reverses sign.

DSO−DPO, FY2024, in days

Only retail reverses sign. The − 16 days of large retailers is exactly the negative credit position described in Part I: cash collected immediately and purchases paid in arrears. Here large firms are the recipients of credit and small retailers the providers.

The + 49 days of information and communications and construction shows large firms bearing long advances in the position of contractor — the territory of families 1-3 (one-off arrears) and 5-3 (cost plus) of Part II.

The claim that “larger firms are the providers of credit” is therefore itself only an average across industries. What decides is not size but the Φ dominant in that industry. The lesson recorded in Part IV — that levels of κ differ structurally across industries so cross-sectional comparison is meaningless — holds on the size axis too.

16.4.5 Implication for Chapter 8

Chapter 8 deduced that a solo business without assets requires κC < 0. The data show that requirement is not met: the under-10m class has DSO of 35 days and DPO of 21, a net 14 days as a provider.

The form differs from what was envisaged at registration, however. The small classes are not extremely κ > 0; rather both DSO and DPO are short. The transactions themselves are small and short. Rather than lying outside the feasible region, they appear to sit at different coordinates.

16.5 Is CCC a leading indicator of the cycle?

16.5.1 The implication tested

Registered implication: the rate of change of CCC leads or is synchronous with the rate of change of sales. In particular, a worsening receivables turnover leads a slowdown in sales.

Correlations between the annual change ΔCCC(t) and the sales growth rate g(t + k) were computed by industry and aggregated over 45 industries, excluding aggregate and short series.

16.5.2 Result

Lag Mean correlation Median Share negative Sign test
Leading k = −1 0.036 0.058 47% p = 0.72
Synchronous k = 0 −0.159 −0.228 69% p = 0.008
Lagging k = +1 0.072 0.118 31% —
Lagging k = +2 0.085 0.035 44% —
Table 16.5: Correlation between ΔCCC(t) and sales growth g(t + k) by lag, over 45 industries.

Synchrony is supported. A worsening CCC and a slowdown in sales occur in the same fiscal year: 31 of 45 industries show a negative correlation, with p = 0.008 on a sign test.

Leading is rejected outright. 47% negative is no information at all (p = 0.72). Change in CCC carries nothing about the following year’s sales.

16.5.3 The synchronous negative correlation may be a denominator effect

The mechanism is likely the reverse of what was assumed. CCC = W∕r has sales in the denominator. If sales fall, then unless inventory and receivables fall at the same rate, CCC worsens by definition.

When the panel by medium for family 2 was treated in Part IV, this was stated explicitly as the alternative: issuance shrinks and the ratio rises mechanically. Section 16.9 separates it here and shows that the denominator effect contributes about 17%.

Claim

Verdict

Change in CCC is synchronous with change in sales

supported; the denominator effect contributes 17% (Section 16.9)

Change in CCC leads change in sales

rejected (p = 0.72)

CCC is a leading indicator of the cycle

rejected
Table 16.6: Verdicts on three claims about the leading property.

16.5.4 That the sign splits by industry is a finding

Thirteen of the 45 industries have |r| > 0.4 in the synchronous correlation.

Strongly negative r Strongly positive r
Pulp, paper and paper products −0.78 Agriculture and forestry +0.80
Fabricated metal products −0.67 Other transport equipment +0.69
Information and communications −0.58 Accommodation and food services +0.54
Production machinery −0.53 Agriculture, forestry and fisheries +0.52
Table 16.7: Industries with |r| > 0.4 in the synchronous correlation (four strongly negative, four strongly positive).

The strongly negative industries are all make-to-order with large inventories and receivables, matching the conditions under which the denominator effect is strong.

What matters is that positive industries exist. A pure denominator effect would make every industry negative. The positive industries have a structure in which CCC grows as sales grow — they build working capital in order to grow — which is the region where the g⋆ of (5.6) binds.

Change in CCC therefore contains components other than the denominator effect. They cannot be separated in these data.

16.6 An observation not anticipated: the long-run rise in CCC

Separately from the tests, a fact not envisaged in advance was observed.

Figure 16.2: CCC and the net credit position, all industries excluding finance and insurance.

As Figure 16.2 shows, the CCC of all industries rose from 24.9 days in FY2000 to 37.2 in FY2024, almost monotonically over 25 years. The net credit position also doubled, from 9.8 to 18.5 days. The Japanese corporate sector as a whole is moving towards holding more working capital.

Remark 16.3 (What the aggregate measures). By Corollary 3.6, credit positions closed within the corporate sector cancel on aggregation. The CCC here is therefore not an indicator of inter-firm credit but the sum of the position against the non-corporate sector and inventory, divided by sales. Indeed, DSO − DPO for all industries in Table 16.3 is 13 days, and most of the gap to CCC = 37.2 days is inventory. The dominant component of the aggregate CCC is inventory. The same reason explains why negative CCC in individual firms does not appear in aggregate.

16.6.1 The growth constraint has not worsened, however

It is tempting to conclude from this that the growth constraint has worsened, since the denominator of (5.6) has risen by half. That inference is wrong.

Over the same period the operating margin m improved by 91%, from 2.62% to 5.01%, outrunning the worsening denominator. The ratio m∕CCC consequently rose from 38.5% to 49.2% (Proposition 14.2).

FY2000 FY2024 Change
CCC 24.9 days 37.2 days +49%
m 2.62% 5.01% +91%
m∕CCC 38.5% 49.2% +28%
Table 16.8: Change in CCC, m and m∕CCC from FY2000 to FY2024.

What is used here is m∕CCC, not the g⋆ = (m + d − I∕r)∕CCC of Corollary 5.7 (Remark 14.3), because d and I were not obtained far enough back.

Remark 16.4 (Discipline in handling ratios). CCC is the denominator of a ratio and says nothing on its own about the growth constraint. Drawing a conclusion from a rise in CCC alone is looking at one half of a ratio. Concluding from one half of a ratio is the same kind of error as the retrospective narrative that Section 12.6 warns against. The difference is that the latter is an interpretation added after the fact, whereas this is filling a shortfall in measurement with inference.

The cause of the rise in CCC itself remains untested. Which of industrial composition, regulation of payment terms, the decline of trade bills, or the level of interest rates contributes is not separated here. The importance of the question is limited, however, since g⋆ has not worsened.

16.7 Levels by industry (for reference)

As the lesson of Part IV has it, cross-sectional comparison of levels cannot be interpreted; the figures are recorded as a reference on the distribution of Φ.

Long CCC Days Short CCC Days
Leasing 210 Food services 5
Real estate 89 Water transport 7
Chemicals 80 Other transport 9
Textiles 78 Entertainment 9
General-purpose machinery 77 Motor vehicles and parts 9
Production machinery 64 Electricity 10
Table 16.9: Industries with the longest and shortest CCC (top six each).

FY2024, excluding aggregate series

The ordering agrees with the types of Part II. Leasing (family 3-1) and real estate acquire an asset first and recover it over time; food services (family 1-1, immediate exchange) sits at κ ≈ 0. The structure of the differences by industry described earlier appears directly.

16.8 Decomposing the rise in CCC

The rise in CCC is decomposed into its causes. The following implication was fixed in advance.

Registered implication: the rise in CCC owes more to the composition effect than to within-industry change, because industries with long CCC have gained weight.

Alternative: if the within-industry effect dominates, working capital has increased in each industry irrespective of composition.

16.8.1 Shift-share decomposition

By Corollary 5.19, the overall CCC is a sales-weighted mean of industry figures, CCC = ∑ ⁡ kwkCCCk. Its difference splits in two.

ΔCCC = ∑ kw¯kΔCCCk⏟ within-industry + ∑ kΔwkCCC¯k⏟ composition (16.5)

Taking ⋅¯ to be the midpoint of the two periods, (16.5) holds exactly with no residual. Substituting w¯ = (w1 + w0)∕2 and CCC¯ = (CCC1 + CCC0)∕2, the right-hand side equals ∑ ⁡ k(wk1CCCk1 − wk0CCCk0). This is not an approximation introduced for measurement but a consequence of CCC being a ratio (Corollary 5.19).

Period ΔCCC Within-industry Composition
2000 →2024 (33 common industries) +11.4 days +9.5 days (82.9%) +1.9 days (17.1%)
2010 →2024 (45 common industries) +10.1 days +9.9 days (98.1%) +0.2 days (1.9%)
Table 16.10: Shift-share decomposition of ΔCCC into within-industry and composition effects.

The implication is rejected. The within-industry effect accounts for 83% to 98%. Since 2010, where the classification is stable, the composition effect is nearly zero. An explanation by the shift towards services does not hold.

The reason the composition effect is small is also clear. Information and communications rose in weight from 0.2% to 5.8%, pushing CCC up by + 3.05 days, while electrical machinery shrank from 6.3% to 2.1% ( − 1.62 days) and advertising from 5.6% to 0.8% ( − 1.59 days): the pushes up and down nearly cancel.

16.8.2 Components of the within-industry effect

The within-industry effect splits into DSO, DIO and DPO.

Period DSO DIO DPO Main cause
2000 →2024 −0.93 +3.49 +6.90 shortening DPO
2010 →2024 +5.26 +4.02 +0.62 lengthening DSO
Table 16.11: The within-industry effect split into DSO, DIO and DPO.

In days of contribution to CCC

Against Corollary 5.20, DSO and DPO correspond to τC and τS and DIO to τinv. Hence:

Period Change in contracts ∑ ⁡ Δτi Change in operations Δτinv
2000 →2024 +5.97 days +3.49 days
2010 →2024 +5.88 days +4.02 days
Table 16.12: The split into change in contracts and change in operations, by Corollary 5.20.

In both periods, change in contracts accounts for about 60%. The rise in CCC originates in changes to contractual terms rather than in demand or inventory management.

The main cause differs by period, and the path of trade bills explains it.

2000 2010 2024
Notes receivable 12.1 days 6.1 days 4.7 days
Notes payable 15.3 days 7.2 days 5.1 days
Table 16.13: Notes receivable and payable, FY2000, FY2010 and FY2024.

Bills fell to below a third during the 2000s. Notes payable lost 8.1 days, from 15.3 to 7.2, and the 6.9-day shortening of DPO is almost entirely explained by this. Bills are a device for creating κS < 0, and their disappearance pushed CCC up.

In the 2010s the decline of bills had run its course and DSO lengthened by 5.26 days. The breakdown is notes receivable − 1.37 days and accounts receivable + 6.62 days. Although bills keep falling, accounts receivable grow by more than enough to offset them. By industry, DSO rose in 28 of 45 industries, with the largest contributions from wholesale (59 →70 days), retail (22 →28 days), information and communications (62 →78 days) and construction (65 →71 days).

Remark 16.5 (Not separable from a shift between accounts). The growth of accounts receivable admits two readings: a genuine lengthening of the collection period, and a shift between accounts accompanying the move to electronically recorded monetary claims. Under the latter, the rise in CCC would be only apparent.

Separating them requires the balance of electronically recorded claims, which is not among the survey items of the Financial Statements Statistics. Under the classification of Section 13.2 this belongs to (iii) non-identification.

16.9 Separating the contemporaneous negative correlation: the contribution of the denominator effect

For the contemporaneous negative correlation observed in Section 16.5, we separate information about demand from the denominator effect inherent in the definition CCC = W∕r.

In log differences, Δln⁡CCC = Δln⁡W −Δln⁡r. Under a pure denominator effect W would not move. Estimating the elasticity

β = Δln⁡W Δln⁡r (16.6)

therefore makes 1 − β the contribution of the denominator effect.

The theoretical value of β is 1. By (5.1), W = CCC ⋅ r, so if CCC is constant then Δln⁡W = Δln⁡r. Hence

Δln⁡CCC = (β − 1)Δln⁡r (16.7)

and the departure of β from 1 is exactly the sales elasticity of CCC. Equation (5.10) of Corollary 5.20 decomposes this movement into change in contracts and change in operations.

Registered implication: Δln⁡W and Δln⁡r are positively correlated; that is, working capital falls when sales fall.

16.9.1 Result

Pooled estimate (44 industries, 946 observations)

β = 0.830

Coefficient of determination

R2 = 0.076

Median of industry-level β

0.625

Standard deviation of industry-level β

1.161

Contribution of the denominator effect 1−β

0.170
Table 16.14: Elasticity of Δln⁡W with respect to Δln⁡r (equation (16.6)).

The implication is supported. Working capital moves almost proportionally with sales, and only about 17% is attributable to the denominator effect. The contemporaneous negative correlation of Section 16.5 carries, for the most part, information from the demand side.

Substituting β = 0.830 into (16.7) gives a sales elasticity of CCC of − 0.170: CCC rises in phases where sales fall. The amplification factor of Remark 5.11 is then larger, so the degree to which a downturn in demand is transmitted to cash strengthens in recessions. Calling 1 − β the “denominator effect” is a computational label, not a claim that CCC has not moved.

16.9.2 Lag structure

By Proposition 3.12, W(t) corresponds to the integral of r over the past τ periods. In industries with long CCC it should also depend on the previous year’s sales. The following was registered in advance.

Registered implication (1): the coefficient β1 on Δln⁡r(t − 1) is larger the longer that industry’s CCC.

Registered implication (2): the total elasticity β0 + β1 including the lag exceeds the contemporaneous-only estimate of 0.830, so the contribution of the denominator effect is smaller than 17%.

The distributed-lag model Δln⁡W(t) = β0Δln⁡r(t) + β1Δln⁡r(t − 1) + 𝜀 was estimated on 886 observations across 43 industries.

β0 (contemporaneous) 0.836
β1 (one-period lag) −0.015
Total elasticity 0.821
R2 0.081
Table 16.15: Estimates of the distributed-lag model.

Both implications are rejected. β1 is nearly zero, and its correlation with CCC is − 0.101 — the sign is also reversed. In industries with CCC < 30 days, β1 = +0.217; in those with CCC ≥ 60 days, − 0.267. The total elasticity falls slightly from 0.830 to 0.821, leaving the contribution of the denominator effect essentially unchanged at 17% to 18%.

Remark 16.6 (Proposition 3.12 is not rejected). Failure to detect a lag structure does not mean equation (3.7) is wrong. The level of CCC is at most 210 days and mostly 30–60 days, which fits within a year at the granularity of annual data. For β1 to be significant, CCC would have to exceed one year, and no such industry exists.

Quarterly data might allow detection, but the quarterly survey rests on the provisional closings of sampled corporations and is therefore affected by closing adjustments.

Remark 16.7 (The confidence is limited). R2 = 0.076 is extremely low: 92% of the variance of Δln⁡W is unexplained by Δln⁡r. The dispersion across industries is also large — β < 0.5 in 14 industries, β > 1.0 in 13, and negative in some (retail − 0.43, leasing − 0.01).

Annual Δln⁡W mixes in year-end inventory adjustment, timing shifts of large transactions, and changes in accounting policy. One may say that the denominator effect is not dominant, but this is insufficient to assert positively that the movement is information about demand.

16.10 The effect of the scope of inventories on the conclusions

The DIO of this chapter uses only “finished goods or merchandise” and excludes work in process and raw materials. Since the Financial Statements Statistics carries “inventories (end of period)” as a separate item, the difference between the two measures the size of the understatement. This section measures that size.

This section is not a test of an implication. It substitutes a different measurement definition on the same data and checks how much the conclusions move.

16.10.1 Two cross-sections

“Inventories (end of period)” was obtained along two cuts. The two identify different variation, and must be read separately.

Cut

Coverage, and the variation identifying β

Obs.
Size cut

10 industries × 11 size strata × FY2015–2024. β is identified by variation between size strata

1,100
Industry cut

62 industries × all sizes × FY2000–2024. β is identified by variation between industries and years

1,364
Table 16.16: The two cuts used to obtain inventories.

The estimate of this chapter (Section 16.9) uses 946 observations across 45 industries, the same design as the industry cut. The figures that correct this chapter are therefore those of the industry cut; the size cut answers a different question. Unless stated otherwise, the figures below are from the industry cut.

16.10.2 The level is understated roughly twofold

The ratio of DIO has a median of 1.99, and the median CCC rises from 28.0 to 43.9 days. For all industries (excluding finance and insurance), FY2000 goes from 24.9 to 38.2 days and FY2024 from 37.2 to 53.5 days.

The size cut gives a median ratio of 1.89 and a difference with median 4.1 days and mean 8.4 days — comparable in magnitude.

Industry DIO goods DIO inv. CCC goods CCC inv.
Manufacturing 19.2 50.4 41.6 72.8
Construction 9.7 33.8 39.8 63.9
All industries (excl. finance and insurance) 18.7 35.0 37.2 53.5
Information and communications 7.5 14.6 58.1 65.2
Other services 8.0 12.2 34.4 38.6
Wholesale 24.2 27.6 32.9 36.3
Food services 3.4 6.1 4.9 7.7
Accommodation 6.5 8.9 21.8 24.2
Retail 24.4 25.4 23.3 24.2
Employment placement and worker dispatch 0.2 0.5 32.8 33.0
Table 16.17: Difference in DIO and CCC by the scope of inventories (all sizes, FY2024, in days).

The difference is of a different order across industries. CCC rises by more than 30% in manufacturing and construction, while retail and employment placement barely move. Divergence arises only in industries that hold work in process — an obvious structure, but large enough to change the ordering of the industry levels in Section 16.7.

16.10.3 The effect on differences is small, but not negligible

Comparing the two definitions for ΔCCC, the industry cut gives a correlation of 0.882 over 1,302 observations, with signs agreeing 86.8% of the time. The size cut (990 observations) gives a correlation of 0.976 and sign agreement of 91.0%: agreement is lower across industries. Because the weight of work in process differs by industry, including cross-industry variation produces a gap.

16.10.4 Correcting the definition worsens the elasticity slightly

Equation (16.6) is estimated on a common sample. Since the observations with W > 0 differ by definition, the comparison is restricted to observations with W > 0 under both definitions.

Cut

Definition of DIO

β R2 Denom. effect 1 − β

Industry cut

finished goods or merchandise only

0.840 0.073 0.160

n = 955

inventories (total)

0.828 0.166 0.172

Size cut

finished goods or merchandise only

0.900 0.092 0.100

n = 733

inventories (total)

0.960 0.213 0.040

Estimate in the text

finished goods or merchandise only

0.830 — 0.170
Table 16.18: Difference in the elasticity β by the scope of inventories, on a common sample.

In both cuts, taking inventories at their total more than doubles the coefficient of determination. Working capital is more nearly proportional to sales when work in process and raw materials are included.

But the direction in which the denominator effect moves is opposite across the two cuts. In the size cut it falls from 0.100 to 0.040, while in the industry cut it rises slightly from 0.160 to 0.172.

Remark 16.8 (Change the cut and the direction changes). Correction shrinks the denominator effect in the size cut and enlarges it in the industry cut. The two are not error: they identify different variation (Table 16.16). Between size strata, larger firms hold more work in process, so taking the total makes W more nearly proportional to sales. Between industries, the weight of work in process itself is dispersed as a characteristic of the industry, so taking the total does not improve proportionality.

The estimate of this chapter is identified by variation between industries and years, so it is the industry cut that applies here. A direction measured in one cut cannot be carried into the other. The range a sample covers is not the same as the range a conclusion reaches.

Remark 16.9 (Without a common sample the sign comes out reversed). Since the observations with W > 0 differ by definition, estimating without aligning the sample gives β of 0.894 and 0.787 in the size cut, yielding the opposite conclusion that the denominator effect increases. Restricted to the common sample the values are 0.900 and 0.960. When measuring the effect of a definition, note that changing the definition changes the composition of the sample.

16.10.5 Verdict

The conclusion of Section 16.9 is maintained, but it is merely maintained, not strengthened.

Claim

Verdict

The absolute level cannot be interpreted

Supported. The median CCC moves from 28.0 to 43.9 days

The effect on analyses of differences and correlations is small

Supported. But the correlation of ΔCCC is 0.882, below the 0.976 of the size cut

The denominator effect is not dominant

Supported. But correction raises it slightly from 0.160 to 0.172
Table 16.19: Verdicts on three claims concerning the scope of inventories, by the industry cut.

All three are supported, but none strongly. That 1 − β is 0.172 means 17% of the increase in working capital is not proportional to sales: not dominant, but not negligible either.

16.11 An observation the simplified capacity constraint does not fit

Remark 2.23 introduced the simplification of treating Cap as a constant. This section records a case in which it does not fit reality. It is a record of a limitation, not a revision of the theory.

16.11.1 The observation

The price schedule of one major full-service fitness club chain was checked as of 2026. The company offers a weekday-daytime-only plan for those aged 60 and over alongside its ordinary plan. The two have identical structures — once a week (up to four visits a month), twice a week (up to eight), and unlimited — and differ only in price.

Facility category Once/wk Twice/wk Unlimited
I 4.0% 10.3% 22.1%
II 4.8% 9.9% 21.5%
III 4.1% 9.6% 21.7%
IV 4.6% 10.0% 21.5%
Table 16.20: Discount rate of the 60-and-over plan, by facility category and usage tier.

Discount of the 60-and-over plan relative to the ordinary plan

In all four categories the discount increases monotonically with usage. It stays around 4% for once a week but reaches about 22% on the unlimited plan. The price ratio from once a week to unlimited is 1.67–1.74 on the ordinary plan and 1.36–1.43 on the 60-and-over plan.

16.11.2 Inconsistency with the simplification

Under equation (2.17), a large discount on the unlimited plan is hard to explain, since it presses on the capacity constraint. Under the general form (2.16) , however, it is explicable: restricting the plan to weekday daytime places supp ⁡ δi within the idle part of Cap(t), so total volume can be increased without worsening the constraint at the peak instant.

That is, the operator manipulates the distribution over time, not the total. The simplification of this work cannot express this device.

16.11.3 Why the theory is not revised from this observation

Remark 16.10 (No generalization from a case). The observation of this section rests on one company’s price list. Part I is an abstraction intended to cover all Φ, while Part IV is a concrete study confined to particular industries and firms. The concrete carries no claim of exhaustiveness.

Rewriting equation (2.17) from an n = 1 observation would propagate a single case across all 28 types. This is of the same form as the retrospective narrativization warned against in Section 12.6: revising the structure of a population from one sample.

A revision of the theory is warranted when a deductive error is found, when the same limitation appears in several independent domains, or when it affects the deductions of Part II. None of these applies here. The observation is therefore recorded, and no revision is made.

16.11.4 The simplified capacity constraint

In connection with Section 8.6, the following implication was fixed in advance.

Registered implication: older cohorts choose pay-per-use over flat-rate contracts. This follows from the preference predicted by socioemotional selectivity theory — that under a limited time horizon one chooses the certain. A flat-rate contract is a bundle of options; pay-per-use is certain.

Alternative: older cohorts have more disposable time and use the facility more often, so the flat rate is more advantageous. Under this account the preference for flat rates rises.

The signs are opposite, so the form is identifiable.

However, no data on consumer choice could be obtained, and the implication is untested. What is needed is the distribution of contract-form choice by age, which operators hold but do not publish.

Only the supply side’s price design was obtained. The discount structure above rests on the premise that older cohorts use the facility more, which is consistent with the alternative and points against the registered implication. But this is the operator’s belief, not the consumer’s choice. It requires the premise that the firm reads demand correctly, and so remains indirect evidence.

16.12 Limitations of this chapter

(1)
The separation of the denominator effect is of low confidence. The elasticity estimate puts the contribution at about 17%, but R2 = 0.076, and most of the variation in Δln⁡W is unexplained.
(2)
The horizontal axis of the four quadrants is not measured. No cross-industry indicator exists for the ease of capturing surplus, so the classification remains one-dimensional, on the demand side alone.
(3)
The interpretation of the growth in accounts receivable is not settled. Section 16.8 excludes industrial composition and explains half by the disappearance of bills, but whether the growth of accounts receivable in the 2010s is a genuine lengthening or a shift between accounts cannot be separated (Remark 16.5).
(4)
The contract choice of older cohorts is untested. As in Section 16.11, no consumer-side choice data could be obtained. The supply side’s price design is consistent with the alternative but remains indirect evidence.
(5)
Inventories are “finished goods or merchandise” only. Work in process and raw materials are excluded, so DIO is understated and the level of CCC comes out shorter than it is. Section 16.10 measures the difference for ten industries and confirms that the effect on analyses of differences and correlations is small, but correcting the 45-industry estimate would require obtaining that item for all industries.

16.13 On both implications being rejected

The direction of credit had the opposite sign; the leading property vanished. Both registered implications failed.

Part IV recorded the effect of pre-registration, and it operated more clearly in this chapter. Had the implications not been fixed beforehand, the contemporaneous negative correlation would very likely have been read as “CCC works as a business-cycle indicator” and the credit position of large firms as “large firms support their counterparties”. Both are retrospective narratives.

The failure of the implications is not a rejection of the framework. The descriptions CCC, κ and Φ function effectively; what failed were conjectures about what these quantities predict. Effectiveness as a tool of description and effectiveness as a tool of prediction are different things.