Income Inequality and Job Creation

Mon, 01 Jan 0001 00:00:00 +0000

The paper establishes a causal link from rising top income shares to reduced net job creation at small firms, working through a bank funding channel rooted in non-homothetic household portfolio allocation: because high-income households hold a smaller fraction of financial wealth in bank deposits (less than one-fifth for the top decile versus two-thirds for the bottom quintile, per the Survey of Consumer Finance), a redistribution of income toward top earners shifts aggregate saving away from deposits toward stocks and bonds. Banks must raise deposit rates to retain funding, which passes through to loan rates; since small, informationally-opaque firms depend disproportionately on bank credit while large firms have direct capital-market access, higher loan rates compress small firms’ net job creation relative to large firms. Using U.S. state-level panel data from 1981 to 2015, a shift-share instrumental variable, and a quantitative general equilibrium model, the paper documents this channel and finds it accounts for 13% of the 4.97 percentage-point rise in large-firm employment share and between 7.5% and 15% of the decline in the labor share since 1980.

Motivating facts (Section 2):

The U.S. net job creation rate of small firms (1–499 employees) declined from roughly +4% in 1980 to near 0% by 2015 and co-moves strongly with the top 10% income share (Figure 1a), suggesting a systematic relationship
SCF data show that the deposit share of financial wealth falls monotonically with income: bottom quintile (Q1) ≈ 65–70%; middle quintile ≈ 45%; top decile < 20% (Figure 2a). Non-financial wealth and stocks/bonds rise sharply with income
FDIC data show deposits account for 93% of total liabilities for the average bank and 75% of total liabilities on aggregate (Figure 2b); average bank raises 98% of deposits in its headquarters state (capital-weighted: 89%), so local deposit supply directly constrains local bank credit

Empirical specification (Section 3): Panel regression at the state–firm-size–year level, 47 states, 1981–2015, 16,435 observations. Dependent variable: net job creation rate (JCR − JDR). Key regressor: interaction of the top 10% income share with a “small firm” dummy (firms 1–499 vs. 500+). Regression includes state–firm-size fixed effects and state–time fixed effects, the latter absorbing all time-varying unobservable state-level factors common to firms of different sizes (e.g., globalization, technology). Identification via a pre-determined share IV: each state’s top 10% income share in 1970 (ten years before the sample) interacted with the leave-one-out national trend in top income shares — exploiting cross-state variation in sensitivity to the aggregate national trend while isolating it from local cyclical conditions.

Empirical results (Table 1, Table 2):

IV estimate: a 10 percentage-point rise in the top 10% income share reduces the relative net job creation rate of small firms by 1.2 percentage points (Table 1, col. 3)
Extensive margin (entry, exit, private-to-public transitions): accounts for approximately 20% of the 1.2pp effect (Table 1, col. 4)
One standard deviation higher top income share (5.4pp) → 0.7pp lower small-firm net JCR (Figure 1b, binned scatter OLS preview)
Counterfactual: had the U.S. top 10% income share remained at its 1980 level (instead of rising ~16pp from 34.5% to 50.5%), small firms’ net job creation rate would be 1.9 percentage points higher — more than 50% above its 2015 level
Bank-level regressions (Table 2): rising top income shares in a bank’s headquarters state lead to higher deposit rates and lower total deposit volumes — consistent with banks raising rates to retain a declining deposit supply

Model (Section 4): General equilibrium model with two types of households and two types of firms. Households differ by income group (high, H, and low, L), each endowed with heterogeneous productivities {si,χ}; households choose consumption, labor supply, and portfolio allocation between bank deposits (providing liquidity services captured by a CES deposit utility term ψd·η) and direct capital investment in public firms. Non-homotheticity: the deposit utility weight is calibrated so high-income households hold fewer deposits per unit of wealth. Firms are either public (large, direct capital-market access, production function with capital share θ and returns to scale γ) or private (small, bank-dependent; labor-only production with bank working capital constraint ϕ̃ governing the loan demand; entry/exit governed by stochastic fixed cost f̃ ~ U[0,f̃max] and a cost of going public κ ~ U[0,κ̃max]). Banks intermediate deposits into loans at a fixed cost, implying a zero-profit loan rate above the deposit rate.

Calibration (Table 3): Two panels:

Panel (a) externally fixed: capital depreciation rate (NIPA), mean US stock market return = 1.08, top 10% income share target = 34.6% (initial, Frank 2009 data), deposit rate = 4% (national average)
Panel (b) internally calibrated to BDS and SCF (early 1980s):
- Labor supply to public firms = 46.9%; private firms = 53.1% (BDS baseline)
- Labor demand to public firms = 46.9%; private firms = 53.1% (matched exactly)
- Deposit share of Q3 household = 0.45; top 10% deposit share = 0.22 (SCF)
- Household discount factor β = 0.9182; deposit utility scale ψd = 0.0632; deposit utility elasticity η = 2.6096
- Capital share in public firms θ; returns to scale γ set to match labor demand targets
- Firm productivity SD σz = 0.0315; bank dependence ϕ̃ and fixed cost bound f̃max matched to Table 1 empirical estimates (intensive and extensive margin); public-share cost bound κ̃max matched to share of firms >500 employees (BDS)

GE experiment (Section 6): Top 10% income share raised permanently from 34.5% to 50.5%, matching Frank (2009) data evolution, via lump-sum transfers from low- to high-income households (holding average income constant to isolate the portfolio reallocation channel). Key aggregate outcomes (Figure 3):

Aggregate deposits fall by more than 2%; savings flow into public firm capital, which rises 2% — the portfolio reallocation effect in levels
Deposit rate rises 0.4pp; loan rate rises 0.7pp; public firm capital return falls 0.14pp — consistent with bank-level empirical estimates
Private firm employment falls ~2%; public firm employment rises ~1%; aggregate employment falls modestly
Private firm employment share falls 0.64 percentage points — the channel explains 13% of the actual 4.97pp BDS decline in employment at firms below 500 employees (1980–2015)
Around one-fifth of the employment share decline comes from the extensive margin (private firm exit and transitions to public status), matching the empirical ratio
Labor share falls 0.3pp, explained by public firms growing relatively larger and being more capital-intensive; this accounts for 7.5% to 15% of the observed 2–4pp decline in the US labor share
Aggregate output falls 0.3%, driven by resource reallocation: private firms have marginal product of labor roughly one-sixth higher than public firms (consistent with the higher small-firm net JCR coefficient), so shifting employment to public firms suppresses aggregate productivity

Welfare effects (Section 6.2, Figure 4): The top 10% experience an increase in consumption-equivalent welfare; bottom 90% experience a decrease. The full model amplifies both effects relative to a counterfactual model with fixed portfolio shares: portfolio reallocation raises top-earner welfare by an additional ~1% (consumption equivalent) relative to the fixed-share benchmark and lowers bottom-earner welfare by ~1% — because in the full model, private firm wages fall (loan rate rise reduces labor demand) while in the fixed-share benchmark private firm wages rise (tops save more deposits, lowering loan rates). Ignoring portfolio heterogeneity thus significantly understates the welfare consequences of income redistribution.

Scope conditions: The mechanism operates through portfolio reallocation only; the paper holds average income constant (lump-sum redistribution) to isolate the channel, abstracting from any direct effects of rising incomes on aggregate savings rates. The IV exploits state-level variation in top income shares; cross-state spillovers in bank credit markets would attenuate estimated coefficients. The model assumes banks cannot replace lost deposits one-for-one with non-deposit liabilities, consistent with institutional frictions documented in the banking literature (Stein, 1998; Hanson et al., 2015). The analysis covers pre-tax income shares; post-tax redistribution through the tax code would dampen the mechanism.

Summary of a forthcoming paper, AI-assisted and human-reviewed. See the linked original for the authoritative claims and full conditions.

In depth

Q1. Why does the portfolio composition of saving matter more than the aggregate savings rate?

The key non-homotheticity is in the composition of saving, not the level: high-income households allocate less than one-fifth of financial wealth to bank deposits while low-income households allocate two-thirds; as income shifts to the top, total deposits decline even if aggregate saving rises modestly. Banks cannot substitute deposit funding with non-deposit liabilities without cost — deposits provide cheap, stable funding because of their unique liquidity and monitoring properties (Stein, 1998; Hanson et al., 2015). An increase in the deposit rate is thus the equilibrating mechanism: banks must bid deposits back from higher-return assets, and the higher funding cost passes through to loan rates.

Q2. Why are small firms disproportionately harmed by higher loan rates?

Small, informationally-opaque firms rely on bank credit for external finance — 92% of small firms in the 1993 National Survey of Small Business Finances use bank loans — while large public firms can raise equity and bonds directly, bypassing banks entirely. When loan rates rise, small firms face a tighter credit constraint on their working capital and fixed costs of operation; the higher loan rate simultaneously reduces their demand for bank credit and raises the value of exiting or transitioning to public status (reducing the private-firm fixed cost burden). Large firms, by contrast, experience lower financing costs as the capital return falls and equity markets absorb more saving — amplifying the relative job creation gap.

The IV uses each state’s top 10% income share in 1970 — ten years before the sample begins, when income shares were flat nationally — interacted with the leave-one-out national trend; any factor driving both job creation outcomes and income inequality in a state would need to have affected firms of different sizes within that state in the same direction as the national trend, while also having had no such effect in all other states. The instrument’s validity rests on: (i) national income share trends after 1980 being driven by aggregate forces (technology, globalization) exogenous to any single state’s labor market; (ii) the pre-1980 period showing no systematic co-movement between state income shares and subsequent employment trends; and (iii) robustness to excluding industries that account for a large share of a state’s employment (Table OA4).

Q4. What explains the aggregate output decline when private firms have higher marginal products?

The output decline of 0.3% arises because the reallocation from private (higher marginal product) to public (lower marginal product) firms outweighs the positive capital accumulation effect: as more saving flows into public firm equity/capital, output would rise, all else equal — but the capital stock increase is modest and aggregate savings rise only slightly, so the dominant effect is misallocation. The marginal product gap between private and public firms is not an assumption of the model but a calibration consequence: matching the empirical estimate that small firms’ net JCR responds more to loan rate changes (Table 1) requires their marginal product to be higher, generating the misallocation loss when resources shift toward large firms.

Q5. How does rising inequality amplify its own effect through welfare and further portfolio reallocation?

In the full model with heterogeneous portfolios, the redistribution from low- to high-income households directly reduces aggregate deposits (because the recipients hold fewer deposits per dollar), which raises deposit and loan rates, which lowers wages at private firms, which further reduces low-income households’ labor income. This GE feedback loop — portfolio composition → bank rates → wages → income distribution → portfolio composition — amplifies the initial redistribution effect by approximately 1 percentage point of consumption-equivalent welfare compared to a model in which households are forced to hold fixed portfolio shares. In the fixed-portfolio model, tops invest more in deposits when they receive transfers, partially offsetting the deposit supply decline, and private firm wages rise — the opposite of the full model.

Q6. What fraction of US macroeconomic trends since 1980 can the channel explain?

The channel accounts for 13% of the 4.97pp rise in large-firm employment share, 7.5–15% of the 2–4pp fall in the aggregate labor share, and a 0.3% output loss from resource misallocation — meaningful but partial contributions to trends that are multi-causal. The partial contributions reflect that rising income inequality is one of several forces driving these trends (technology adoption, trade, market concentration, capital-skill complementarity); the paper explicitly abstracts from these other forces by using lump-sum transfers that hold average income constant, isolating the portfolio reallocation channel alone.

Q7. What happens to firm entry and exit under rising inequality?

A higher loan rate raises the effective cost of operating as a private firm (working capital is more expensive), reducing the threshold productivity level below which private firms exit and raising the threshold above which private firms find it worthwhile to incur the IPO-type cost of going public; both margins reduce the number of private firms in equilibrium, consistent with declining business dynamism. The model implies approximately one-fifth of the employment share decline at small firms comes from this extensive margin — closely matching the data decomposition from the BDS — and the public firm share rises by 0.003pp, consistent with the small but positive trend in the share of large-firm establishments observed in the data.

FDIC data show deposits represent 93% of average bank liabilities and 75% of aggregate bank liabilities; banks rely on their headquarters-state deposit base for the vast majority of funding because regulatory and institutional frictions constrain inter-state deposit gathering — even the four largest US banks (JP Morgan, Citi, Wells Fargo, Bank of America) raise over 70% of deposits in their headquarters state. The literature (Stein, 1998; Jakab and Kumhof, 2015) establishes that deposits provide uniquely stable, cheap funding that cannot be replaced at equivalent cost by wholesale liabilities or interbank borrowing; any substitution requires costly premium over the deposit rate, implying the attenuation bias if anything understates the true causal effect on loan rates.

Key concepts

non-homothetic deposit preference : the empirical regularity that the share of financial wealth allocated to bank deposits declines with income — two-thirds for the bottom quintile, under one-fifth for the top decile; this non-homotheticity means that a mean-preserving income redistribution toward top earners reduces the aggregate deposit supply relative to total saving, the paper’s foundational portfolio channel.

pre-determined share IV : the paper’s instrumental variable for state-level top income shares: each state’s 1970 top 10% income share interacted with the leave-one-out national trend in top 10% shares; identifies causal effects by exploiting differential state sensitivity to national inequality trends, purged of local cyclical factors and large-firm wage premia.

private versus public firm : the model’s key firm heterogeneity; private firms are small, bank-dependent (working capital constrained), and pay fixed operating costs; public firms are large, equity-financed, and face no bank credit constraint. The intensive-margin effect of higher inequality (rising loan rates) and extensive-margin effect (higher exit rates, more IPO transitions) both compress the private firm employment share.

deposit rate pass-through : the mechanism by which a decline in aggregate deposit supply forces banks to raise deposit rates to retain funds; the higher deposit rate is passed through to loan rates via the bank’s zero-profit condition, raising the cost of credit for bank-dependent private firms by approximately twice the deposit rate increase (0.7pp loan rate rise for 0.4pp deposit rate rise in the model).

business dynamism channel : the extensive margin of the paper’s mechanism — rising top income shares increase loan rates, which increase private firm exit rates and the rate of private-to-public firm transitions, reducing firm entry and contributing to documented trends of falling startup rates and declining business dynamism in the US since 1980.

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